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1
Kawaguchi, Satoshi, and Atsushi Morikawa. "Preparation of poly(ether ketone)s having phenyl, biphenyl, and terphenyl side groups and comparison of their properties." High Performance Polymers 30, no. 1 (2016): 67–75. http://dx.doi.org/10.1177/0954008316679493.
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Three kinds of bis(aromatic fluoride) compounds, 3,5-bis(4-fluorobenzoyl)biphenyl (1), 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″-terphenyl (2), and 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″:4″,1′′′-quaterphenyl (3), were synthesized by cross-coupling of the corresponding triflates with phenylboronic acid. Linear poly(ether ketone)s (1x, 2x, and 3x) having phenyl, biphenyl, and terphenyl side groups, respectively, were prepared by the polycondensation of the bis(aromatic fluoride) compounds with bisphenol A (a) and 4,4′-dihydroxybiphenyl (b) in N-methyl-2-pyrrolidone. The obtained poly(ether ketone)s were characterized by X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The structure–property relationships of these poly(ether ketone)s were examined and compared with those of poly(ether ketone)s (4x) having no side group, which were prepared from 3,5-bis(4-fluorobenzoyl)benzene (4). The properties of the poly(ether ketone)s, solubilities, and thermal properties were compared and discussed based on the length of the side groups.
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Wolfe, Patricia S., Yemanlall Lochee, Dhanjay Jhurry, Archana Bhaw-Luximon, and Gary L. Bowlin. "Characterization of Electrospun Novel Poly(ester-ether) Copolymers: 1,4-Dioxan-2-one and D,L-3-Methyl-1,4-dioxan-2-one." Journal of Engineered Fibers and Fabrics 6, no. 4 (2011): 155892501100600. http://dx.doi.org/10.1177/155892501100600409.
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Introduction: Because tissue engineering scaffolds serve as a temporary environment until new tissue can be formed, their mechanical performance, thermal properties, and biocompatibility are critical for maintaining their functionality. The goal of this study was to electrospin scaffolds from copolymers containing varying amounts of 1,4-Dioxan-2-one (DX) and D,L-3-Methyl-1,4-dioxan-2-one (DL-3-MeDX), and characterize their mechanical and thermal properties. Methods and Results: Image tool analysis of scanning electron micrographs revealed the presence of DL-3-MeDX causes the fiber diameter of the scaffold to decrease as compared to polydioxanone (PDO). Uniaxial tensile testing revealed increasing amounts of DL-3-MeDX in the copolymer decreases scaffold peak stress, strain at break and toughness. Modulated differential scanning calorimetry was used for thermal analysis of the scaffolds and showed that increasing amounts of DL-3-MeDX causes a decrease in the melting as well as crystallization temperatures. Conclusion: Based on the results of the mechanical and thermal properties of these copolymer scaffolds, it is evident that these constructs could be functional in a variety of biomedical engineering applications.
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Huang, Rui, Jinshui Yao, Qiuhong Mu, Dan Peng, Hui Zhao, and Zhizhou Yang. "Study on the Synthesis and Thermal Stability of Silicone Resin Containing Trifluorovinyl Ether Groups." Polymers 12, no. 10 (2020): 2284. http://dx.doi.org/10.3390/polym12102284.
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Silicone resin is a high-temperature resistant material with excellent performance. The improvement of its thermal stability has always been the pursuit of researchers. In this paper, a sequence of silicone resins containing trifluorovinyl ether groups were prepared by the co-hydrolysis-polycondensation of methyl alkoxysilane monomers and {4-[trifluorovinyl(oxygen)]phenyl}methyldiethoxysilane. The structures of the silicone resins were characterized by FT-IR and 1H NMR. The curing process of them was studied by DSC and FT-IR spectra, and results showed that the curing of the resins included the condensation of the Si-OH groups and the [2 + 2] cyclodimerization reaction of the TFVE groups, which converted to perfluorocyclobutane structure after curing. The thermal stability and thermal degradation behavior of them was studied by TGA and FT-IR spectra. Compared with the pure methyl silicone resin, silicone resins containing TFVE groups showed better thermal stability under both N2 and air atmosphere. Their hydrophobic properties were characterized by contact angle test. Results showed that PFCB structure also improved the hydrophobicity of the silicone resin.
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Manohar, Murli, Prem P. Sharma, and Dukjoon Kim. "Intercalated Poly (2-acrylamido-2-methyl-1-propanesulfonic Acid) into Sulfonated Poly (1,4-phenylene ether-ether-sulfone) Based Proton Exchange Membrane: Improved Ionic Conductivity." Molecules 26, no. 1 (2020): 161. http://dx.doi.org/10.3390/molecules26010161.
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A series of hybrid proton exchange membranes were synthesized via in situ polymerization of poly (2-acrylamido-2-methyl-1-propanesulfonic acid) PMPS with sulfonated poly (1,4-phenylene ether-ether-sulfone) (SPEES). The insertion of poly (2-acrylamido-2-methyl-1-propanesulfonic acid) PMPS, between the rigid skeleton of SPEES plays a reinforcing role to enhance the ionic conductivity. The synthesized polymer was chemically characterized by fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance 1H NMR spectroscopy to demonstrate the successful grafting of PMPS with the pendent polymer chain of SPEES. A variety of physicochemical properties were also investigated such as ion exchange capacity (IEC), proton conductivity, water uptake and swelling ratio to characterize the suitability of the formed polymer for various electrochemical applications. SP-PMPS-03, having the highest concentration of all PMPS, shows excellent proton conductivity of 0.089 S cm−1 at 80 °C which is much higher than SPEES which is ~0.049 S cm−1. Optimum water uptake and swelling ratio with high conductivity is mainly attributed to a less ordered arrangement polymer chain with high density of the functional group to facilitate ionic transport. The residual weight was 93.35, 92.44 and 89.56%, for SP-PMPS-01, 02 and 03, respectively, in tests with Fenton’s reagent after 24 h. In support of all above properties a good chemical and thermal stability was also achieved by SP-PMPS-03, owing to the durability for electrochemical application.
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Hu, Qun Hui, Wen Xiao Wang, Shu Bo Wang, et al. "Preparation of Poly (aryl ether) Anion Ionomers with N-Methyl Imidazolium Groups." Advanced Materials Research 560-561 (August 2012): 221–25. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.221.
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Anion exchange membranes based on poly(aryl ether oxadiazole)s (FPAEO) were prepared by quaternization of bromomethylated FPAEO with N-methyl imidazole. The structures of the obtained polymers were characterized and confirmed with 1H-NMR measurement. The physical and electrochemical properties of anion exchange membranes were also studied. The conductivity of FPAEO-xMIM membranes were almost higher than 10−2 S/cm at room temperature. In addition, TGA revealed that the AEMs based on imidazolium salts have excellent thermal stability. The experimental results suggested that the obtained AEMs may be potential membranes for anion exchange membrane fuel cells
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Wu, Ti, Wei Min Zhang, NA Yang, and Jia Ling Pu. "A Novel Thermo-Sensitive Polymer Film and its Imaging Properties." Key Engineering Materials 373-374 (March 2008): 658–61. http://dx.doi.org/10.4028/www.scientific.net/kem.373-374.658.
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Three copolymers containing isobutyl p-styrenesulfonate (IBSS) and carboxyl units, i.e. methyl methacrylate (MMA) and methacrylic acid (MAA), were synthesized and their chemical structures and thermal behaviors were investigated by using TGA, DSC, FTIR and other methods. Films were prepared by using the synthesized copolymers in combination with a bisvinyl ether compound, i.e. 2,2-bis(4-(2-(vinyloxy)ethoxy)phenyl)propane (BVPP), to applied onto an aluminum plate. Crosslinking and de-crosslinking reactions would readily take place when the polymer films were baking treated at 100 oC and 200 oC for a short period of time, respectively. Along with the chemical structural changes during thermal treatments, an affinity change was achieved from being insoluble to completely soluble in neutral water. A positive-working and neutral water-developable imaging material was proposed and preliminary studies on the imaging properties were conducted.
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Mao, Hua, Yong You, Lifen Tong, Xiaohe Tang, Renbo Wei, and Xiaobo Liu. "Dielectric properties of poly(arylene ether nitrile ketone) copolymers." High Performance Polymers 31, no. 8 (2018): 901–8. http://dx.doi.org/10.1177/0954008318808570.
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A series of poly(arylene ether nitrile ketone) (PENK) random copolymers are successfully synthesized by the nucleophilic aromatic substitution polymerization of 2,6-dichlorobenzonitrile, 4,4′-difluorobenzophenone with various bisphenol monomers (4,4′-biphenol, bisphenol A, phenolphthalein, and hydroquinone). Compared with poly(arylene ether ketone), the PENK copolymers possess better solubility in polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, and so on. Because of the different molecular structures, the PENK copolymers exhibit thermal properties with their glass transition temperature ( T g) in the range of 171–237°C and 5% weight loss temperature ( T d) ranging from 409°C to 554°C. Moreover, all polymers with an intrinsic viscosity of approximately 1 dL/g show excellent film-forming properties and outstanding mechanical strength higher than 85 MPa. The temperature dependence of the dielectric constant and dielectric loss of all derived copolymers is stable before their T g. The breakdown strength of the hydroquinone-derived PENK copolymer is as high as 253 kV/mm, resulting in an energy storage density of 1.00 J/cm3. These solvent processable PENK copolymers are potential dielectric candidates for high temperature applications.
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Chen, Ying, and Jun Fen Sun. "Study on Poly(ether imide)/Amino-Modified Sillica Hybrid Membranes." Materials Science Forum 789 (April 2014): 218–23. http://dx.doi.org/10.4028/www.scientific.net/msf.789.218.
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Poly (ether imide) (PEI) membrane with many good properties, such as chemical resistance, biocompatibility, good thermal, and mechanical properties, has been widely used in filtration and biomedical applications. SiO2particles containing amine groups can be a good enzyme immobilization carrier. Organic-inorganic hybrids of poly (ether imide) and amino-modified SiO2were in situ prepared via sol-gel process in the presence of tetraethylortho silicate (TEOS) in a mixed solvent of N, N-Dimethylacetamide/1-Methyl-2-pyrrolidone (DMAc/NMP). The effects of casting solution composition on the membrane morphological structure and performance were investigated. The dispersion of the inorganic and organic phase in the nanoscale was possible with addition of (3-aminopropyl) triethoxysilane (APTES) as shown by field emission electron microscopy. Membranes with different ratio of APTES/TEOS have quite different properties. Mechanical properties evaluation such as rupture elongation ration and tensile strength tests of the hybrid membranes were carried out. Fourier transform infrared spectroscopy (FTIR), pure water fluxes and water contact angle of the hybrid membranes were also characterized. The results show that poly (ether imide)/amino-modified SiO2hybrid membranes have high static adsorption capacity for lysozyme (Lys). Moreover, mechanical properties of the hybrid membranes greatly improve compared to pure PEI membranes.
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Yang, Wanying, Jiaqi Wang, Lingjiang Jia, Jingyi Li, and Shouxin Liu. "Stereo-Complex and Click-Chemical Bicrosslinked Amphiphilic Network Gels with Temperature/pH Response." Gels 9, no. 8 (2023): 647. http://dx.doi.org/10.3390/gels9080647.
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Stimulus-responsive hydrogels have been widely used in the field of drug delivery because of their three-dimensional pore size and the ability to change the drug release rate with the change in external environment. In this paper, the temperature-sensitive monomer 2-methyl-2-acrylate-2-(2-methoxyethoxy-ethyl) ethyl ester (MEO2MA) and oligoethylene glycol methyl ether methacrylate (OEGMA) as well as the pH-sensitive monomer N,N-Diethylaminoethyl methacrylate (DEAEMA) were used to make the gel with temperature and pH response. Four kinds of physicochemical double-crosslinked amphiphilic co-network gels with different polymerization degrees were prepared by the one-pot method using the stereocomplex between polylactic acid as physical crosslinking and click chemistry as chemical crosslinking. By testing morphology, swelling, thermal stability and mechanical properties, the properties of the four hydrogels were compared. Finally, the drug release rate of the four gels was tested by UV–Vis spectrophotometer. It was found that the synthetic hydrogels had a good drug release rate and targeting, and had great application prospect in drug delivery.
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Chen, Sheng, Qing Kang Zheng, Zhen Bao Li, Xin Lei Wang, and Jian Wu Lan. "Synthesis and Properties of New Poly( Amide-Imide)s Based on Imide Dicarboxylic Acid." Advanced Materials Research 332-334 (September 2011): 1722–26. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.1722.
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Two kinds of imide dicarboxylic acid monomers, 4,4'-bis(trimellitimido) diphenyl ether Ⅰ and p-trimellitimido-benzoic acid Ⅱ were successfully synthesized from 4,4'-diaminodiphenyl ether and p-aminobenzoic acid with trimellitic anhydride respectively.and used to synthesize a series of new aromatic poly(amide-imide)s (PAIs) by the tri-phenyl phosphite-activated polycondensation method. The preparation of PAIs was carried out using triphenyl phosphate and pyridine symtem. The PAIs had inherent viscosities of 0.55–1.46 dL g-1. PAI films were obtained by casting their N-Methyl-2-pyrrolidone (NMP) solution. Their cast films had tensile strengths ranging from 37.4 to 83.9 MPa. The glass-transition temperatures (measured by differential scanning calorimetry) were in the range of 265-310°C. According to thermogravimetric analysis, the polymers were fairly stable up to temperature around 420°C, and 10% weight losses in the temperature range of 474-550°C in nitrogen, that showed good thermal stabilities of these polymers.
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Plachouras, Nikolaos V., and Marinos Pitsikalis. "Statistical Copolymers of N–Vinylpyrrolidone and 2–Chloroethyl Vinyl Ether via Radical RAFT Polymerization: Monomer Reactivity Ratios, Thermal Properties, and Kinetics of Thermal Decomposition of the Statistical Copolymers." Polymers 15, no. 8 (2023): 1970. http://dx.doi.org/10.3390/polym15081970.
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The radical statistical copolymerization of N–vinyl pyrrolidone (NVP) and 2–chloroethyl vinyl ether (CEVE) was conducted using the Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization technique, employing [(O–ethylxanthyl)methyl]benzene (CTA-1) and O–ethyl S–(phthalimidylmethyl) xanthate (CTA-2) as the Chain Transfer Agents (CTAs), leading to P(NVP–stat–CEVE) products. After optimizing copolymerization conditions, monomer reactivity ratios were estimated using various linear graphical methods, as well as the COPOINT program, which was applied in the framework of the terminal model. Structural parameters of the copolymers were obtained by calculating the dyad sequence fractions and the monomers’ mean sequence lengths. Thermal properties of the copolymers were studied by Differential Scanning Calorimetry (DSC) and kinetics of their thermal degradation by Thermogravimetric Analysis (TGA) and Differential Thermogravimetry (DTG), applying the isoconversional methodologies of Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS).
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Lee, Min-Jae, Seon-Young Park, and A.-Young Sung. "Poly (Ethylene Glycol) Methyl Ether Methacrylate-Based Hydrogel and Cerium(IV) Oxide Nanoparticles as Ophthalmic Lens Material." Micromachines 12, no. 9 (2021): 1111. http://dx.doi.org/10.3390/mi12091111.
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The functional hydrogel lens containing 2-hydroxyethylmethacrylate (HEMA) was manufactured by thermal polymerization. The physical properties of the produced hydrogel lens were measured and analyzed. In this study, HEMA, ethylene glycol dimethacrylate (EGDMA), and azobisisobutyronitrile (AIBN) were used for thermal copolymerization. Additionally, poly (ethylene glycol) methyl ether methacrylate (PEGMEMA), 3-(Triethoxysilyl) propyl isocyanate (TEPI), and cerium(Ⅳ) oxide nanoparticles were used as additives to make a functional hydrogel lens. The mixture was heated at 100 °C for 90 min to produce the hydrogel ophthalmic lens by the cast mold method. The resulting physical properties showed that the water content and refractive index of the sample were in the ranges of 38.06~42.11% and 1.426~1.436, respectively. The addition of cerium oxide nanoparticles lowered the contact angle and allowed the hydrogel lens to block UV light. The tensile strength was also improved by 52.13% through cerium oxide nanoparticles, and up to 123.4% by using TEPI. Based on the results of this study, the produced ophthalmic lens is suitable for durable, UV-blocking high-performance lenses.
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Pouresmaeel-Selkjani, Peyman, Mohsen Jahanshahi, and Majid Peyravi. "Mechanical, thermal, and morphological properties of nanoporous reinforced polysulfone membranes." High Performance Polymers 29, no. 7 (2016): 759–71. http://dx.doi.org/10.1177/0954008316656742.
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The effect of three different diphenols including 1,1′-thiobis(2-naphthol) (TBN), 2,2′-thiobis(4-methyl phenol) (TBMP) and curcumin (CUR) used in the preparation of sulfonated poly(ether sulfide sulfone) (SPESS) on the mechanical, thermal, and morphological properties of polysulfone (PSf) membranes was studied. In this regard, the morphological characteristics of the nanoporous membranes were explored by developed image analyzer program. Based on the obtained results, PSf membrane modified by SPESS-TBN copolymer showed the best nominal tensile strength in comparison to the other samples with the value of 206 MPa. The optimum real tensile strength with the value of 322 MPa was observed for SPESS-TBMP membrane. It was found that the addition of SPESS, improved the mechanical and thermal properties as well as the performance of membranes. Inspections of scanning electron microscopic images for evaluation of the void properties of membranes revealed that there were 42.3, 8.76, 41.45 and 15.92% of void contents within the structures of neat PSf membrane, SPESS-CUR, SPESS-TBMP and SPESS-TBN, respectively. Moreover, some conceptual relations between morphological and mechanical properties were presented. Finally, the effect of the membrane chemical structure on the mechanical, thermal, and morphological properties was discussed in this study.
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Morikawa, Atsushi, Fumi Miyata, and Jun Nishimura. "Synthesis and properties of polyimides from 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl." High Performance Polymers 24, no. 8 (2012): 783–92. http://dx.doi.org/10.1177/0954008312453062.
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Diamines, namely, 1,4-bis(4-amino-2-phenylphenoxy) benzene (1) and 4,4′-bis(4-amino-2-phenylphenoxy) biphenyl (2), were synthesized from 4-fluoro-3-phenyl nitrobenzene. Two series of polyimides were synthesized from these diamines with nine types of dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. The polyimides were characterized by x-ray diffraction, differential scanning calorimetry, thermogravimetry and dynamic mechanical analysis. The polyimides from 1 and 2 had a glass transition temperature in the range of 221–254°C and 222–271°C, respectively, and all the polymers were amorphous. The structure–property relationships of these polyimides were examined and compared with those of the previously prepared analogous polyimides from the bis(4-amino-2-biphenyl)ether (3). Water absorption and dielectric constants ( ∊) of the polyimides were compared and discussed on the basis of imide content per repeating unit.
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Driva, Paraskevi, Panagiotis Bexis, and Marinos Pitsikalis. "Radical copolymerization of 2-vinyl pyridine and oligo(ethylene glycol) methyl ether methacrylates: Monomer reactivity ratios and thermal properties." European Polymer Journal 47, no. 4 (2011): 762–71. http://dx.doi.org/10.1016/j.eurpolymj.2010.09.032.
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Singh, Rajendra K., Rooma Mago Mehta, and R. G. Bass. "Synthesis and characterization of extended poly(phenylquinoxalines) containing carbonyl, ether and sulphide linking groups." High Performance Polymers 7, no. 4 (1995): 481–92. http://dx.doi.org/10.1088/0954-0083/7/4/010.
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A series of eight novel extended poly(phenylquinoxalines) (PPQs) containing carbonyl, ether and sulphide linking groups were prepared by polycondensation of 4,4'-bis(phenylglyoxalyl-4-phenoxy-4'-benzoyl)diphenyl sulphide, I-D, and 4,4'-bis(phenyl glyoxalyl-4-phenylthio-4'-benzoyl)diphenyl sulphide, 2-D, with four aromatic bis(o-diamines) in m-cresol. The primary objective of this study was to correlate the effect of these linkages on the various properties such as solubility, thermal stability and glass transition temperature of the PPQs. Polymerization of 1-D was carried out in an oil bath maintained at 195-200C whereas polymerization of 2-D was performed at ambient temperature. The polymers prepared were soluble in m-cresol. dimethylsulphoxide, N,N-dimethylacetamide, I-methyl-2-pyrrolidinone and chlorinated hydrocarbon solvents, and formed tough transparent, yellow fingernail-creasable films from chloroform solutions. The inherent viscosities ranged between 0.44 and 0.96 dl g' '. The glass transition temperatures were nearly identical for both systems and ranged from 217-231 'C for polymers prepared from l-D and from 215-233"C for polymers prepared from 2-D. The PPQs having carbonyl and stJlphide linking groups had higher thermal stability in comparison to PPQs having carbonyl, ether and sulphide linkages. The temperature of 10% weight loss for I-D ranged from 484-496 'C in air and 485-516"C in helium whereas those for 2-D ranged from 538-579 XC in air and 522-549 in helium.
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Tan, Jihuai, Bowen Liu, Qinghe Fu, Liwei Wang, Junna Xin, and Xinbao Zhu. "Role of the Oxethyl Unit in the Structure of Vegetable Oil-Based Plasticizer for PVC: An Efficient Strategy to Enhance Compatibility and Plasticization." Polymers 11, no. 5 (2019): 779. http://dx.doi.org/10.3390/polym11050779.
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Developing vegetable oil-derived primary plasticizers for poly(vinyl chloride) (PVC) is still a challenge because of their insufficient compatibility. As described in this work, we report the synthesis of plasticizers through the esterification of polyethylene glycol methyl ether and dimer acid, in which dimer acid is renewable material prepared via a two-step reaction (1) the hydrolysis of fatty acids from soybean oil at 70 °C and (2) subsequent Diels–Alder reaction at 250 °C. The resulting plasticizers, dimer acid-derived polyethylene glycol methyl ether esters (DA-2n, 2n = 2, 4, 6 or 8 referring to the number of oxethyl units per molecule), were blended with PVC. It was found that the tensile properties, transparency, and thermal stability of plasticized PVC (PVC-DA-2n) increased significantly with an increase in the number of oxyethyl units. Fourier-transform infrared spectroscopy analysis revealed that its good compatibility can be attributed to the strong interaction between oxyethyl units and PVC. As the number of the oxyethyl units of plasticizer increased, the glass transition temperature (Tg) of the corresponding plasticized PVC samples decreased from 62.3 (PVC-DA-2) to 35.4 °C (PVC-DA-8). Owing to the excellent plasticization of DA-8, the performances of PVC-DA-8 were comparable or better than that of the PVC plasticized using commercial dioctyl terephthalate (DOTP). The simple but efficient method of this study provides a new avenue for the preparation of vegetable oil-based plasticizers for PVC.
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Jin, Cuihong, and Xiuling Zhu. "Synthesis and physicochemical properties of sulfonated poly(aryl ether) PEMs containing phthalazinone and oxadiazole moieties." High Performance Polymers 30, no. 3 (2017): 274–82. http://dx.doi.org/10.1177/0954008317691585.
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In this work, 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (2F-Oz) is synthesized and successfully polymerized with 4-(4-hydroxyaryl)-phthalazin-1-one (DHPZ) through polycondensation to produce poly(ether 1,3,4-oxidiazole) containing phthalazinone units (PPEO) with intrinsic viscosity 1.54 dL g−1. A series of sulfonated poly(ether-1,3,4-oxidiazole)s (SPPEOs) with different degrees of sulfonation are prepared via postsulfonation reaction. The chemical structure of PPEO and SPPEOs was characterized through FT-IR and proton nuclear magnetic resonance, respectively. SPPEOs have excellent film-forming properties and readily dissolve in polar aprotic solvents, such as dimethyl sulfoxide, N-methyl-2-pyrrolidone (NMP), and so on. The water uptake of these SPPEO membranes with measured ion-exchange capacity of 1.13–1.61 mmol g−1 was 15.7–34.1% at 25°C and 17.9–59.8% at 60°C, and swelling ratio was 5.9–14.2% at 25°C and 6.6–18.1% at 60°C, respectively. The proton conductivity of SPPEO-1.61 is 0.045 S cm−1 at 30°C and 0.065 S cm−1 at 80°C, and the tensile strength of the SPPEO-1.61 is 48 MPa, and its elongation at break was 21%. The thermal and chemical stability of the SPPEOs is also examined.
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Zhang, Xiao-Lan, Xiao-Ling Liu, Qiu-Ying Wang, Zhen-Zhong Huang, and Shou-Ri Sheng. "Synthesis and characterization of novel fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties." High Performance Polymers 31, no. 5 (2018): 485–96. http://dx.doi.org/10.1177/0954008318801905.
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4-(4-Trifluoromethylphenyl)-2,6-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]pyridine (9FPBAPP), as a new aromatic diamine, was prepared by a modified Chichibabin reaction of 4-(4-nitro-2-trifluoromethylphenoxy)acetophenone with 4-triflouromethylbenzaldehyde, followed by a catalytic reduction. A series of fluorinated poly(ether imide)s containing pyridine and/or phenylphosphine oxide moieties were prepared from bis(3-aminophenyl)phenylphosphine oxide (BAPPO), 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), and 9FPBAPP via a conventional two-step thermal imidization procedure with various mole ratios of BAPPO and 9FPBAPP. All the polymers were amorphous and soluble in common organic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone and had Tg’s of 277–285°C, 5% weight loss temperature of 521–550°C in nitrogen. Furthermore, high char yields and good limited oxygen index values indicated that these polymers exhibited good thermal stability and flame-retardant property. Tough and flexible polymer films also had good mechanical properties with tensile strengths of 75–99 MPa, tensile moduli of 1.1–1.6 GPa, and elongations at break of 12%–24% and low dielectric constants of 2.81–3.53 (1 MHz), as well as high optical transparency with the ultraviolet cutoff wavelength in the range of 350–384 nm.
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Harada, Miyuki, and Takuya Matsumoto. "Thermal Conductivity and Orientation Structure of Liquid Crystalline Epoxy Thermosets Prepared by Latent Curing Catalyst." Crystals 14, no. 1 (2023): 47. http://dx.doi.org/10.3390/cryst14010047.
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Improvements in the performance of electronic devices necessitate the development of polymer materials with heat dissipation properties. Liquid crystalline (LC) epoxies have attracted attention because of the orientation of their polymer network chains and their resultant high thermal conductivity. In this study, a diglycidyl ether of 1-methyl-3-(4-phenylcyclohex-1-enyl)benzene was successfully synthesized as an LC epoxy and the LC temperature range was evaluated via differential scanning calorimeter (DSC). The synthesized LC epoxy was cured with m-phenylenediamine (m-PDA) as an amine-type curing agent and 1-(2-cyanoethyl)-2-undecylimidazole (CEUI) as a latent curing catalyst, respectively. The LC phase structure and domain size of the resultant epoxy thermosets were analyzed through X-ray diffraction (XRD) and polarized optical microscopy (POM). High thermal conductivity was observed in the m-PDA system (0.31 W/(m·K)) compared to the CEUI system (0.27 W/(m·K)). On the other hand, in composites loaded with 55 vol% Al2O3 particles as a thermal conductive filler, the CEUI composites showed a higher thermal conductivity value of 2.47 W/(m·K) than the m-PDA composites (1.70 W/(m·K)). This difference was attributed to the LC orientation of the epoxy matrix, induced by the hydroxyl groups on the alumina surface and the latent curing reaction.
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Zivkovic, Nikola, Slobodan Serbanovic, Emila Zivkovic, Mirjana Kijevcanin, and Predrag Stefanovic. "Wet flue gas desulphurisation procedures and relevant solvents thermophysical properties determination." Chemical Industry 68, no. 4 (2014): 491–500. http://dx.doi.org/10.2298/hemind130610074z.
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In order to mitigate climate change, the priority task is to reduce emissions of greenhouse gases, including sulfur oxides, from stationary power plants. The legal framework of the European Union has limited the allowable emissions of gases with harmful effects and fulfillment of this obligation is also ahead of the Republic of Serbia in the following years. In this paper categorization of wet procedures for sulfur oxides removal is given. Wet procedure with the most widespread industrial application, lime/limestone process, has been described in detail. In addition, the procedures with chemical and physical absorption and solvent thermal regeneration, which recently gained more importance, have been presented. Experimentally determined thermophysical and transport properties of commercially used and alternative solvents, necessary for the equipment design and process optimization, are also given in the paper. The obtained values of densities and viscosities of pure chemicals - solvents, polyethylene glycol 200 (PEG 200), polyethylene glycol 400 (PEG 400), tetraethylene glycol dimethyl ether (TEGDMA), N-methyl-2-pyrolidon (NMP) and dimethylaniline (DMA), measured at the atmospheric pressure, are presented as a function of temperature.
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Huang, Nengkun, Fan Wang, Ruihao Zhang, et al. "Biodegradable Hydrogenated Dimer Acid-Based Plasticizers for PLA with Excellent Plasticization, Thermal Stability and Gas Resistance." Molecules 29, no. 11 (2024): 2526. http://dx.doi.org/10.3390/molecules29112526.
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The use of vegetable oil-dervied plasticizers to enhance the flexibility of polylactic acid (PLA) has received much attention due to their renewability, inexpensiveness and biodegradation. However, the double bonds in vegetable oil-based plasticizers limit their compatibility with PLA, resulting in PLA-derived products with reduced flexibility. Herein, we examined soybean oil-derived hydrogenated dimer acid-based polyethylene glycol methyl ether esters (HDA-2n, 2n = 2, 4, 6 or 8, referring to the ethoxy units) developed via the direct esterification of saturated hydrogenated dimer acid and polyethylene glycol monomethyl ethers. The resulting HDA-2n was first used as a plasticizer for PLA, and the effects of the ethoxy units in HDA-2n on the overall performance of the plasticized PLA were systematically investigated. The results showed that, compared with PLA blended with dioctyl terephthalate (DOTP), the PLA plasticized by HDA-8 with the maximum number of ethoxy units (PLA/HDA-8) exhibited better low-temperature resistance (40.1 °C vs. 15.3 °C), thermal stability (246.8 °C vs. 327.6 °C) and gas barrier properties. Additionally, the biodegradation results showed that HDA-8 could be biodegraded by directly burying it in soil. All results suggest that HDA-8 could be used as green alternative to the traditional petroleum-based plasticizer DOTP, which is applied in the PLA industry.
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Faghihi, Khalil, Masoumeh Soleimani, Shabnam Nezami, and Meisam Shabanian. "Thermal and optical properties of new poly(amide-imide)-nanocomposite reinforced by layer silicate based on chiral n-trimellitylimido-L-valine." Macedonian Journal of Chemistry and Chemical Engineering 31, no. 1 (2012): 79. http://dx.doi.org/10.20450/mjcce.2012.59.
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Two new samples of poly(amide-imide)-montmorillonite reinforced nanocomposites containing N-trimellitylimido-L-valine moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 5 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N-trimellitylimido-L-valine (3) with 4,4′-diaminodiphenyl ether 4 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PA-nanocomposite films (5a) and (5b) with 10 and 20 % silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.
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Lee, Dong Hoon, Hye Suk Park, Dong Wan Seo, and Whan Gi Kim. "Organic-Inorganic Nano Composite Membranes of Sulfonated Poly(ether Sulfone-Ketone) Copolymer and SiO2 for Fuel Cell Application." Materials Science Forum 534-536 (January 2007): 97–100. http://dx.doi.org/10.4028/www.scientific.net/msf.534-536.97.
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Novel bisphenol-based wholly aromatic sulfonated poly(ether sulfone-ketone) copolymer and organic-inorganic composite membranes were prepared for operation 80°C in polymer electrolyte membrane fuel cell (PEMFCs). The copolymer were synthesized by direct aromatic nucleophilic substitution polycondensation of 4,4-difluorobenzophenone, 2,2’-disodiumsulfonyl- 4,4’-fluorophenylsulfone (40mole% of bisphenol A) and bisphenol A. Polymerization proceeded quantitatively to high molecular weight in N-methyl-2-pyrrolidinone at 180°C. Organic-inorganic composite membranes were obtained by mixing organic polymers with hydrophilic SiO2 obtained by sol-gel process. The polymer and a series of composite membranes were studied by FT-IR, 1HNMR, differential scanning calorimetry (DSC) and thermal stability. The proton conductivity as a function of temperature decreased as SiO2 content increased, but methanol permeability decreased. The nano composite membranes were found to poses all requisite properties; Ion exchange capacity (1.2meq./g), glass transition temperatures (164-183), and low affinity towards methanol (4.63-1.08x10-7 cm2/S).
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Deokar, Satish S., Makarand D. Joshi, Asiya M. Tamboli, et al. "Aromatic Polyesters Containing Ether and a Kinked Aromatic Amide Structure in the Main Chain: Synthesis and Characterisation." Coatings 12, no. 2 (2022): 181. http://dx.doi.org/10.3390/coatings12020181.
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A novel bisphenol containing preformed multiple ether and amide linkages, N, N′-Bis (4-hydroxyphenoxyphenylene) isophthalamide (IPCD), was prepared and analysed by spectroscopic methods. New aromatic polyesters were prepared by polycondensation of IPCD with 1, 3-benzene diacidchloride and/or 1, 4-benzene diacidchloride. These obtained polyesters were structurally analysed by infra-red spectroscopy, measurements of inherent viscosity, wide-angle X-ray diffraction patterns, and thermal techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility tests in organic solvents. The synthesised polyesters had high molecular weights, as indicated by their inherent viscosities from 0.67 to 0.78 dL/g in N-methyl-2-pyrrolidone. The incorporation of ether and kinked aromatic amide moieties in the main polyester chains greatly affected the properties of these aromatic polyesters. The prepared polyesters readily dissolved in amide-type polar aprotic solvents and pyridine, indicating their solution processability. The DSC curves above the polyesters showed glass transition temperatures of 194 to 269 °C. TGA indicated that these newly obtained polyesters were stable up to 301 °C and retained a 39 to 48% weight at 900 °C. W-XRD analyses showed that the newly synthesised polyesters were amorphous, which is reflected in their solubility behaviour.
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Han, Guanglu, Jie Lv, and Mohan Chen. "ZIF-67 Incorporated Sulfonated Poly (Aryl Ether Sulfone) Mixed Matrix Membranes for Pervaporation Separation of Methanol/Methyl Tert-Butyl Ether Mixture." Membranes 13, no. 4 (2023): 389. http://dx.doi.org/10.3390/membranes13040389.
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Mixed matrix membranes (MMMs) with nano-fillers dispersed in polymer matrix have been proposed as alternative pervaporation membrane materials. They possess both promising selectivity benefiting from the fillers and economical processing capabilities of polymers. ZIF-67 was synthesized and incorporated into the sulfonated poly (aryl ether sulfone) (SPES) matrix to prepare SPES/ZIF-67 mixed matrix membranes with different ZIF-67 mass fractions. The as-prepared membranes were used for pervaporation separation of methanol/methyl tert-butyl ether mixtures. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and laser particle size analysis results show that ZIF-67 is successfully synthesized, and the particle size is mainly between 280 nm and 400 nm. The membranes were characterized by SEM, atomic force microscope (AFM), water contact angle, thermogravimetric analysis (TGA), mechanical property testing and positron annihilation technique (PAT), sorption and swelling experiments, and the pervaporation performance was also investigated. The results reveal that ZIF-67 particles disperse uniformly in the SPES matrix. The roughness and hydrophilicity are enhanced by ZIF-67 exposed on the membrane surface. The mixed matrix membrane has good thermal stability and mechanical properties, which can meet the requirements of pervaporation operation. The introduction of ZIF-67 effectively regulates the free volume parameters of the mixed matrix membrane. With increasing ZIF-67 mass fraction, the cavity radius and free volume fraction increase gradually. When the operating temperature is 40 °C, the flow rate is 50 L·h−1 and the mass fraction of methanol in feed is 15%, the mixed matrix membrane with ZIF-67 mass fraction of 20% shows the best comprehensive pervaporation performance. The total flux and separation factor reach 0.297 kg·m−2·h−1 and 2123, respectively.
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Majed Jari Mohammed, Majed Jari Mohammed, Abdul Amir H. Kadhum Abdul Amir H Kadhum, and Adnan Ibrahim Mohammed and Sameer H. Abbood Al Rekabi Adnan Ibrahim Mohammed and Sameer H Abbood Al Rekabi. "Synthesis of One New Sugar Imine Molecule." Journal of the chemical society of pakistan 42, no. 1 (2020): 103. http://dx.doi.org/10.52568/000622.
Full textAbstract:
In this research, the molecule Nand#39;-((E)-5-methoxy-2-((1-((2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)-4,5-dihydro-1H-1,2,3-triazol-4-yl)methoxy) benzylidene)-4-methyl-1,2,3-thiadiazole-5-carbohydrazide were synthesized and characterized by several conventional analysis methods. Its physical properties and thermal stability was studied. The synthesis was conducted based on D-glucose using concept of click chemistry reaction mechanism. Some of the reaction was conducted using microwave irradiation. The synthesis steps initiated by adding propargyl bromide to 2- hydroxy-5-methoxy benzaldehyde under vigorous measure of moister isolated environment to produce propargyl ether(5-methoxy-2-(prop-2-yn-1-yloxy)benzaldehyde) 3 in which has terminal triple bond. In parallel a glycocyl azide was prepared by applying glycocyl acetate (acetate for protection) via bromination and then substituted by treatment with sodium azide to produce glycocyl azide in which actively reacted with terminated triple bond by click reaction in the present of Cu(II) catalyst. The coupling reaction of terminal alkyle group in compound 3 with azide group of (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-azidotetrahydro-2H-pyran-3,4,5-triyl triacetate) has given high yield of triazole. The produced triazole molecule is triazole(2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-(4-((2-formyl-4-methoxy)methyl)-1H-1,2,3-triazole-1-yl)tetrahydro-2H-pyran-3,4,5,-triyacetate) 7 undergoes further reaction to substitute carbonyl of the aromatic with hydrazide by applying 4-methyl-1,2,3-thiadiazole-5-carbohydrazide reagent. The glycocyl acetate was de-esterifide by sodium methoxide to remove the acetate protection. The structure of all these synthesized molecules was confirmed by FTIR, H1NMR, C13 NMR.
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Majed Jari Mohammed, Majed Jari Mohammed, Abdul Amir H. Kadhum Abdul Amir H Kadhum, and Adnan Ibrahim Mohammed and Sameer H. Abbood Al Rekabi Adnan Ibrahim Mohammed and Sameer H Abbood Al Rekabi. "Synthesis of One New Sugar Imine Molecule." Journal of the chemical society of pakistan 42, no. 1 (2020): 103. http://dx.doi.org/10.52568/000622/jcsp/42.01.2020.
Full textAbstract:
In this research, the molecule Nand#39;-((E)-5-methoxy-2-((1-((2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)-4,5-dihydro-1H-1,2,3-triazol-4-yl)methoxy) benzylidene)-4-methyl-1,2,3-thiadiazole-5-carbohydrazide were synthesized and characterized by several conventional analysis methods. Its physical properties and thermal stability was studied. The synthesis was conducted based on D-glucose using concept of click chemistry reaction mechanism. Some of the reaction was conducted using microwave irradiation. The synthesis steps initiated by adding propargyl bromide to 2- hydroxy-5-methoxy benzaldehyde under vigorous measure of moister isolated environment to produce propargyl ether(5-methoxy-2-(prop-2-yn-1-yloxy)benzaldehyde) 3 in which has terminal triple bond. In parallel a glycocyl azide was prepared by applying glycocyl acetate (acetate for protection) via bromination and then substituted by treatment with sodium azide to produce glycocyl azide in which actively reacted with terminated triple bond by click reaction in the present of Cu(II) catalyst. The coupling reaction of terminal alkyle group in compound 3 with azide group of (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-azidotetrahydro-2H-pyran-3,4,5-triyl triacetate) has given high yield of triazole. The produced triazole molecule is triazole(2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-(4-((2-formyl-4-methoxy)methyl)-1H-1,2,3-triazole-1-yl)tetrahydro-2H-pyran-3,4,5,-triyacetate) 7 undergoes further reaction to substitute carbonyl of the aromatic with hydrazide by applying 4-methyl-1,2,3-thiadiazole-5-carbohydrazide reagent. The glycocyl acetate was de-esterifide by sodium methoxide to remove the acetate protection. The structure of all these synthesized molecules was confirmed by FTIR, H1NMR, C13 NMR.
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Bifulco, Aurelio, Angela Marotta, Jessica Passaro, et al. "Thermal and Fire Behavior of a Bio-Based Epoxy/Silica Hybrid Cured with Methyl Nadic Anhydride." Polymers 12, no. 8 (2020): 1661. http://dx.doi.org/10.3390/polym12081661.
Full textAbstract:
Thermosetting polymers have been widely used in many industrial applications as adhesives, coatings and laminated materials, among others. Recently, bisphenol A (BPA) has been banned as raw material for polymeric products, due to its harmful impact on human health. On the other hand, the use of aromatic amines as curing agents confers excellent thermal, mechanical and flame retardant properties to the final product, although they are toxic and subject to governmental restrictions. In this context, sugar-derived diepoxy monomers and anhydrides represent a sustainable greener alternative to BPA and aromatic amines. Herein, we report an “in-situ” sol–gel synthesis, using as precursors tetraethylorthosilicate (TEOS) and aminopropyl triethoxysilane (APTS) to obtain bio-based epoxy/silica composites; in a first step, the APTS was left to react with 2,5-bis[(oxyran-2-ylmethoxy)methyl]furan (BOMF) or diglycidyl ether of bisphenol A (DGEBA)monomers, and silica particles were generated in the epoxy in a second step; both systems were cured with methyl nadic anhydride (MNA). Morphological investigation of the composites through transmission electron microscopy (TEM) demonstrated that the hybrid strategy allows a very fine distribution of silica nanoparticles (at nanometric level) to be achieved within a hybrid network structure for both the diepoxy monomers. Concerning the fire behavior, as assessed in vertical flame spread tests, the use of anhydride curing agent prevented melt dripping phenomena and provided high char-forming character to the bio-based epoxy systems and their phenyl analog. In addition, forced combustion tests showed that the use of anhydride hardener instead of aliphatic polyamine results in a remarkable decrease of heat release rate. An overall decrease of the smoke parameters, which is highly desirable in a context of greater fire safety was observed in the case of BOMF/MNA system. The experimental results suggest that the effect of silica nanoparticles on fire behavior appears to be related to their dispersion degree.
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Abdel-Rahman, Mona A., Waleed A. El-Said, Eman M. Sayed, and Aboel-Magd A. Abdel-Wahab. "Synthesis, Characterization of Some Conductive Aromatic Polyamides/Fe3O4 NPs/ITO, and Their Utilization for Methotrexate Sensing." Surfaces 6, no. 1 (2023): 83–96. http://dx.doi.org/10.3390/surfaces6010007.
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Here, we have synthesized four series of polyamide-conductive polymers and used them to modify Fe3O4 NPs/ITO electrodes. The ability of the modified electrodes to detect methotrexate (MTX) anticancer drug electrochemically was investigated. Synthesis of the target-conducting polyamides, P1a–d, P2a–d, P3a, P3b, P3d, and P4c-d, based on different aromatic moieties, such as ethyl 4-(2-(4H-pyrazol-4-ylidene)hydrazinyl)benzoate, diphenyl sulfone, diphenyl ether or phenyl, has been achieved. They were successfully prepared in good yield via solution–polycondensation reaction of the diamino monomers with different dicarboxylic acid chlorides in the presence of N-methyl-2-pyrrolidone (NMP) as a solvent and anhydrous LiCl as a catalyst. A model compound 4 was synthesized from one mole of ethyl-4-(2-(3, 5-diamino-4H-pyrazol-4-ylidene)hydrazinyl) benzoate (diamino monomer) (3) with two moles benzoyl chloride. The structure of the synthesized monomers and polymers was confirmed by elemental and spectral analyses. In addition, thermogravimetric analysis evaluated the thermal stabilities of these polyamides. Furthermore, the morphological properties of selected polyamides were examined using an scanning electron microscope. Polyamide/Fe3O4/ITO electrodes were prepared, and the electrochemical measurements were performed to measure the new polyamides’ conductivity and to detect the MTX anticancer drug in phosphate buffer saline using cyclic voltammetry. The polyamides (P3b and P4b)/Fe3O4/ITO electrodes showed the highest sensitivity and reversibility towards MTX.
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Bakvand, Pegah Mansouri, Dong Pan, Andrit Allushi, and Patric Jannasch. "Influence of Monomer Configuration on the Performance of Poly(quaterphenyl piperidinium) Anion Exchange Membranes." ECS Meeting Abstracts MA2023-02, no. 39 (2023): 1894. http://dx.doi.org/10.1149/ma2023-02391894mtgabs.
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Polymeric anion exchange membranes (AEM)s are crucial components in many electrochemical energy devices where the performance is strongly influenced by the ionic conductivity, mechanical robustness, and thermochemical stability of the materials.1,2 AEMs are susceptible to degradation due to the chemically aggressive nature of the hydroxide ion, which significantly restricts their long-term applicability, especially at elevated temperature.3,4 Improving the polymer backbone design by, e.g., eliminating ether linkages from the polymer backbone is an approach to improve alkaline stability.5 Moreover, by introducing multi-ring aromatic segments, the rigidity, hydrophobicity, and “blockiness” of the polymer backbone increase, leading to mechanical robustness and enhanced microphase separation (ionic clustering) of the AEM.6 Obviously, the configuration of the multi-ring aromatic segments will have an influence, which can be used to tune and improve the properties of the polymers and AEMs.7,8 In the present project, we investigated the influence of the configuration of quaterphenyl monomers in poly(quaterphenyl piperidinium)s on the corresponding AEM properties. Three different monomers (isomers) with different connectivity between the four rings were investigated: para-para, para-meta, and meta-meta. The polymers were prepared by superacid-mediated Friedel-Crafts type polycondensations (polyhydroxyalkylations) involving N-methyl piperidone and the respective quaterphenyl. Subsequently, the polymers were fully quaternized with methyl iodide to prepare a series of ether-free poly(quaterphenyl piperidinium)s with different backbone configurations and chain flexibility. In this presentation, the influence of the quaterphenyl configuration on AEM properties such as water uptake, hydroxide conductivity, ionic clustering, thermal and chemical stability will be discussed. Li, C.; Baek, J. B., Nano Energy 2021, 87, 106162. Aili, D.; Rykær Kraglund, M.; Rajappan S.C.; Serhiichuk, D.; Xia Y.; Deimede V.; Kallitsis, J.; Bae, C.; Jannasch, P.; Henkensmeier, D.; Jensen, J.O., ACS Energy Lett. 2023, 8, 1900–1910. Mohanty, A. D.; Bae, C., Mater. Chem. A 2014, 2(41), 17314-17320. Jeon, J. Y.: Park, S.; Han, J.; Maurya, S.; Mohanty, A. D.; Tian, D.; Saikia, N.; Hickner, M. A.; Ryu, C. Y.; Tuckerman, M. E.; Paddison, S. J.; Kim, Y. S.; Bae, C., Macromolecules 2019, 52(5), 2139–2147. Olsson, J. S.; Pham, T. H.; Jannasch, P., Funct. Mater. 2018, 28(2), 1702758. Liu, M.; Hu, X.; Hu, B.; Liu, L.; Li, N., Membr. Sci. 2022, 642, 119966. Pham, T. H.; Olsson, J. S.; Jannasch, P., Mater. Chem. A 2019, 7(26), 15895-15906. Lee, W-H;Park, E. J.; Junyoung, H.; Shin, D. W.; Kim, Y. S.; Bae, C., ACS Macro Lett. 2017, 6(5), 566–570.
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Stampfer, Léopold, Cécile Bouilhac, Tiphaine Mérian, et al. "Investigation of the Reaction between a Homemade PEEK Oligomer and an Epoxy Prepolymer: Optimisation of Critical Parameters Using Physico–Chemical Methods." Polymers 16, no. 6 (2024): 764. http://dx.doi.org/10.3390/polym16060764.
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Several researchers have examined the interest in using a thermoplastic to increase thermoset polymers’ shock resistance. However, fewer studies have examined the nature of the mechanisms involved between both kinds of polymers. This was the objective of our work, which was carried out using a gradual approach. First, we describe the synthesis of a poly(ether ether ketone) oligomer (oPEEK) with hydroxyl terminations from the reaction of hydroquinone and 4,4′-difluorobenzophenone in N-methyl-2-pyrrolidone. Then, the main physicochemical properties of this oligomer were determined using different thermal analyses (i.e., differential scanning calorimetry (DSC), thermogravimetric (ATG), and thermomechanical analyses) to isolate its response alone. The chemical characterisation of this compound using conventional analytical chemistry techniques was more complex due to its insolubility. To this end, it was sulfonated, according to a well-known process, to make it soluble and enable nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC) experiments. Additional information about the structural and chemical characteristics of the oligomer and its average molecular weight could thus be obtained. The synthesis of an oligoPEEK with α,ω-hydroxyl end-groups and a molecular weight of around 5070 g/mol was thus confirmed by NMR. This value was in accordance with that determined by SEC analysis. Next, the reaction of oPEEK with an epoxy prepolymer was demonstrated using DSC and dynamic rheometry. To this end, uncured mixtures of epoxy prepolymer (DGEBA) with different proportions of oPEEK (3, 5, 10 and 25%) were prepared and characterised by both techniques. Ultimately, the epoxy-oPEEK mixture was cured with isophorone diamine. Finally, topological analyses were performed by atomic force microscopy (AFM) in tapping mode to investigate the interface quality between the epoxy matrix and the oPEEK particles indirectly. No defects, such as decohesion areas, microvoids, or cracks, were observed between both systems.
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Bakirova, Indira N., and Tatiana A. Mineeva. "INFLUENCE OF CHAIN EXTENDER STRUCTURE AND RIGID BLOCK SIZE ON STRUC-TURE AND PROPERTIES OF ESTER URETHANE THERMOPLASTIC ELASTOMERS FOR CONSTRUCTIONAL PURPOSES." ChemChemTech 68, no. 6 (2025): 117–25. https://doi.org/10.6060/ivkkt.20256806.7192.
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The influence of the structure of the chain extender and the size of the rigid block on the properties of urethane thermoplastic elastomers obtained on the basis of oligobutylene glycol adipate with a molecular weight of 1800 and 4,4'-diphenylmethane diisocyanate is considered. An aromatic diol, 2,2-bis-[4-(2-hydroxyethoxy)phenyl]propane, and an aliphatic diol, 1,4-butanediol, were used as a chain extenders.The synthesis of thermoplastic elastomers was carried out at a general molar ratio of [NCO]/[OH] = 1, which ensured the production of a linear polymers with terminal hydroxyl and isocyanate groups. At the same time, the formulations provided for a variation in the size of the diolurethane hard block due to a change in the molar ratio [diisocyanate]/[chain extender] = 2-3/1-2. X-ray diffraction analysis showed that samples obtained using an aromatic diol are amorphous, while the use of the aliphatic diol leads to the formation of amorphous-crystalline thermoplastic elastomers. The absence of a crystalline phase in the samples is due to the introduction of aromatic nuclei, methyl groups in the form of side branches and flexible simple ether bonds into their rigid block due to the use of 2,2-bis-[4-(2-hydroxyethoxy)-phenyl]-propane. As a result, the degree of phase separation decreases, phase compatibility increases and the ability of the polymer to elastic recovery improves. The use of 1,4-butanediol leads to the formation of a more ordered polymer structure, which contributes to the crystallization of the oligoester block. It has been established that replacing the aliphatic chain extender with an aromatic one results in obtaining low-modulus thermoplastic elastomers, reducing their hardness values, no residual deformations after removing the load, a slight decrease in strength, and an increase in thermal stability. An increase in the length of the rigid block causes an increase in the elastic modulus, strength, and hardness of the material. For citation: Bakirova I.N., Mineeva T.A. Influence of chain extender structure and rigid block size on structure and properties of ester urethane thermoplastic elastomers for constructional purposes. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 6. P. 117-125. DOI: 10.6060/ivkkt.20256806.7192.
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Himbert, Gerhard, Dieter Fink, and Martina Stürm. "Cycloadditionen, XXI [1]. 2-Methyl-2,3-butadiensäure-arylester; Synthese und thermische Reaktivität / Cycloadditions, XXI [1] Aryl 2-methyl-2,3-butadienoates; Synthesis and Thermal Reactivity." Zeitschrift für Naturforschung B 49, no. 1 (1994): 63–75. http://dx.doi.org/10.1515/znb-1994-0114.
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Abstract The substituted phenyl, 1-naphthyl or the 9-anthrylmethyl esters of the 2-methyl-(or 2-phenyl)-2,3-alkadienoic acids (see 4 a -g , 9 a -d and 12a,b) are synthesized by condensation of the allenic acids 2 a -d with the substituted phenols 3 a -g , with 1-naphthol (8) or with 9-anthrylmethanol (11) in the presence of dicyclohexyl carbodiimide (DCC) and a catalytic amount of 4-dimethylaminopyridine (DMAP). An alternative route is the reaction of the acid chloride la with the phenols 3 a -c (see formation of 4 a -c) in the presence of triethylamine. All these compounds (except 12a) undergo the intramolecular Diels-Alder (IMDA)-reaction to form the tricycles 6 a -g , 10 a-d and 13. The enol ether 6a is hydrolized during chromatography to give the tricyclic ketone 7. The influence of the geminal methyl group on the rate of the IMDA-reaction is investigated. 9-Anthryl-and (2,4,6-cycloheptatrien-1-on-2-yl)-2-methyl-2,3-butadienoate (15, 17), formed by reaction of 2-methyl-2,3-butadienoyl chloride (1a) with 9-anthrone (14) and 2-tropolone (16) isomerise spontaneously to the IMDA-products 19 and 18.
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Pham, Quoc-Thai, and Badril Azhar. "Synthesis and Characterizations of Novel Copolymers with Zwitterionic Moiety-Based Solid Polymer Electrolytes for Solid-State Lithium Metal Battery." ECS Meeting Abstracts MA2024-01, no. 2 (2024): 461. http://dx.doi.org/10.1149/ma2024-012461mtgabs.
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Electric vehicles (EVs) have become the dominant choice in the automotive industry, displacing internal combustion engine vehicles (ICEVs) to some extent. The development of high-efficiency batteries is essential to meet these market demands. Conventional lithium-ion batteries (LIBs), which consist of a cathode, anode, separator, and liquid electrolyte (such as 1M LiPF6 in carbonate solvents), have been widely utilized in portable electronic devices, hybrid electric vehicles (HEVs), and EVs. This popularity is attributed to their relatively high energy density and extended cycle life [1]. However, LIBs with energy density exceeding 240 Wh kg-1 face challenges in terms of thermal stability, potentially leading to fire and explosions by overcharging or accidental cell penetration. This drawback significantly hinders their application in automotive settings [2, 3]. In response to these safety concerns, there is a shift towards incorporating solid-state electrolytes (SSEs) as a replacement for liquid electrolytes. SSEs include solid polymer electrolyte (SPE), inorganic solid electrolyte (ISE), and composite polymer electrolyte (CPE). Solid-state lithium metal batteries (SSLMBs) incorporating SPE hold significant promise for advancing energy storage technologies due to their high energy density and improved safety features. However, the low ionic conductivity and ionic transference number of SPEs present challenges in their application for solid-state batteries. This work focuses on designing novel copolymers with polar soft unit and zwitterionic unit to address these challenges. In this study, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and sulfobetaine methacrylate (SBMA) were selected as the polar soft segment and zwitterionic unit, respectively. Various ratios of PEGMEA/SBMA in copolymers were synthesized and characterized, and the resultant SPEs consisting of resultant copolymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared. Subsequently, their electrochemical, thermal, mechanical, and morphological properties were systematically investigated. The copolymers-based SPEs exhibited improved electrochemical properties. The optimized SPE comprising the copolymer with the molar ratio of PEGMEA/SBMA = 1/3 and 50 wt% LiTFSI exhibited the ionic conductivity of approx. 2×10–4 S cm–1, lithium-ion transference number of approx. 0.3, Li+ diffusion coefficient of 15×10-12 cm² s-1, and oxidation stability of 5.2 V (vs. Li/Li+) at 25 oC. Additionally, the mechanical properties of such SPEs were assessed, showing improved tensile strength (up to approx. 6 MPa) and Young’s modulus (up to approx. 83 MPa) with increasing SBMA content. The selected SPE with the best electrochemical properties was sandwiched between a Li metal electrode and a LiFePO4 electrode to assemble a SSLMB. As a result, the discharge capacity (DC) at 0.1 C-rate and room temperature was approx. 170 mA h g–1. Furthermore, the DC at a 0.5 C-rate was approx. 146 mA h g–1, and the capacity retention of 70% obtained after 470 cycles. In summary, this work demonstrates the potential of tailored copolymers with zwitterionic moiety-based SPEs for SSLMB. The comprehensive characterization and performance assessments provide valuable insights into the design and optimization of polymer electrolytes for next-generation energy storage systems. The copolymers and corresponding SPEs underwent characterization through various techniques such as DSC, SEM, XRD, and FTIR. The Ionic conductivity of the SPEs was determined by analyzing the results obtained from EIS measurement. The lithium-ion diffusion coefficient (DLi+) for SPE in a symmetric SSLMB cell, Li/SPE/Li, was also calculated based on the EIS results [4]. The oxidation stability window of the SPE was measured using the linear sweep voltammetry technique, and the ion transfer number was determined using the Evans-Vincent-Bruce method [5]. References 1. Wu, F., et al., Chemical Society Reviews, 2020. 49(5): 1569-1614. 2. Wang, Q., et al., Journal of Power Sources, 2012. 208: p. 210-224. 3. Wu, Y.S., et al., ACS Sustainable Chemistry & Engineering, 2022. 10(22):7394-7408. 4. Pham, Q.T., et al., ACS Applied Energy Materials, 2023. 6 (6):3525-3537. 5. Evans, J., et al., Polymer, 1987. 28: 2324-2328. Figure 1
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Dinari, Mohammad, and Ahmad Reza Rajabi. "Structural, thermal and mechanical properties of polymer nanocomposites based on organosoluble polyimide with naphthyl pendent group and layered double hydroxide." High Performance Polymers 29, no. 8 (2016): 951–59. http://dx.doi.org/10.1177/0954008316665678.
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In this study, a soluble aromatic polyimide (PI) with naphthyl pendent group was initially synthesized by the reaction of pyromellitic dianhydride (PMDA) with 5-methyl- N,N-bis(4-nitrophenyl)naphthalen-1-amine. Then, via co-precipitation reaction of zinc nitrate hexahydrate and chromium nitrate nonahydrate, Zn/Cr-layered double hydroxide (LDH) was synthesized using hydrothermal techniques. Finally, different novel nanocomposites (NCs) based on PI and Zn/Cr-LDH (1, 2, 4 wt%) were produced through in situ polymerization. The resulting materials were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetry analysis (TGA), field emission scanning electron microscopy, transmission electron microscopy, and mechanical testing. According to the TGA results, the prepared NCs showed high thermal stability at higher temperature due to the good dispersion and homogeneity of Zn/Cr-LDH in polymeric matrix. Consequently, the mechanical properties of the synthesized NCs were enhanced by the incorporation of 2 wt% Zn/Cr-LDH in the polymer matrix.
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H., R. Prajapati, and V. Doshi A. "Study of azo ester mesogenic homologous series 2-(4'-n-alkoxy benzoyloxy)- naphthyl-1-azo-4" -methyl benzenes." Journal of Indian Chemical Society Vol. 86, May 2009 (2009): 470–74. https://doi.org/10.5281/zenodo.5810110.
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Chemistry Department, C. U. Shah Science College, Ahmedabad-380 014, Gujarat, India <em>E-mail</em> : drhrprajapati@yahoo.co.in Chemistry Department, Matushri Virbaima Mahila Science and Home Science,College, Rajkot-360 007, Gujarat, India <em>Manuscript received 6 November 2008, accepted 15 January 2009</em> Mesogenic homologous series : 2-(4<em>'</em>-<em>n</em>-alkoxy benzoyloxy)-naphthyl-1-azo-4<em>"</em>-metbyl benzenes is synthesized to understand the effects of structural variation on mesogenic characteristics. All the members of the homologous series exhibit enantiotropic nematic mesophase with threaded type of textures. Smectic mesophase does not occur in any homologue of the series even in the monotropic condition. Well-known odd-even effect is observed in the nematic isotropic transition curve. Thermal stabilities and liquid crystalline properties are compared with other structurally identical homologous series. Melting and transition temperatures are determined by hot stage polarizing microscope. Analytical data support the structures of molecules.
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Malathi, Mahalingam, Palathurai Subramaniam Mohan, Raymond J. Butcher, and Chidambaram Kulandaisamy Venil. "Benzimidazole quinoline derivatives — An effective green fluorescent dye for bacterial imaging." Canadian Journal of Chemistry 87, no. 12 (2009): 1692–703. http://dx.doi.org/10.1139/v09-139.
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A one-pot synthesis of benzimidazoles by condensing naphthyl or quinoline aldehyde with benzene-1,2-diamine has been reported. IR, 1H and 13C NMR, mass spectral, and CHN analyses were used to elucidate the structures of the products. The molecular structural correlation in the optical properties of the quinoline and naphthalene benzimidazoles was explored. The fluorescence quantum yield ([Formula: see text]) and time-resolved fluorescent lifetime of the quinoline benzimidazoles derivatives were estimated. The influence of solvent polarity and pH on the optical property of quinoline derivatives was illustrated. To explore the bioanalytical applicability, the thermal stability by TG–DTA analysis and the cytogenetic analysis of 3-(1H-benzoimidazol-2-yl)-2-chloro-8-methyl-quinoline (1b) compound were carried out. The fluorescent staining ability of 1b was analyzed and also compared with the normal Gram staining in the bacterium.
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Gomathi, G., T. Srinivasan, D. Velmurugan, and R. Gopalakrishnan. "A bluish-green emitting organic compound methyl 3-[(E)-(2-hydroxy-1-naphthyl)methylidene]carbazate: spectroscopic, thermal, fluorescence, antimicrobial and molecular docking studies." RSC Advances 5, no. 56 (2015): 44742–48. http://dx.doi.org/10.1039/c5ra04964d.
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Chang, Wanhyuk, Eun Heui Kang, Heon Jun Jeong, Wonjoon Choi та Joon Hyung Shim. "Inkjet Printing of PrBa0.5Sr0.5Co1.5Fe0.5O5+ δ Cathode for High-Performance Proton Ceramic Fuel Cells". ECS Meeting Abstracts MA2023-01, № 54 (2023): 353. http://dx.doi.org/10.1149/ma2023-0154353mtgabs.
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Ceramic fuel cells have been actively studied and are in the commercialization stage because of their economic and efficiency advantages, including the lack of precious metal catalysts, including Pt, fuel flexibility, and high efficiency. Solid oxide fuel cells (SOFCs) are the most typical type of ceramic fuel cell that conduct oxide ions. However, the operating temperature of SOFCs is high (>700 °C) owing to the high activation energy required for ion conduction. Prolonged operation at high temperatures can cause chemical and mechanical degradation in materials and peripheral parts, discouraging their use as long-time stationary generators, which is the main target market for SOFCs. For these reasons, expectations and interest in proton ceramic fuel cells (PCFCs) have recently increased owing to excellent power and durability exhibited at intermediate temperatures (<600 °C). According to recent reports, the durability of PCFC is superior to that of SOFC, even when methane fuel or city gas is used. The cathode reaction accounts for the highest resistance in PCFC operation. Therefore, the development of a high-performance cathode is the biggest factor for the success of PCFCs. To develop a high-performance cathode, the following factors must be optimized: 1) surface and interface shapes and components that can maximize the charge transfer reaction, and 2) porous microstructure that can effectively deliver oxygen gas to the reaction sites, and 3) electrolyte-electrode adhesion at the interface. The potential of inkjet printing (IJP) as a fabrication technology capable of optimizing these structures and components was recently confirmed by our group. IJP has attracted attention as a thin-film deposition technology that can produce complex and sophisticated microstructures, such as various multi-component ceramic materials, while controlling them at the nano-level. Recently, solution processes such as spin coating, tape casting, and screen printing have been frequently adopted in device manufacturing owing to their advantages such as simple accessibility and convenient management. However, fabricating films with nanoscale thickness is very difficult. Moreover, the precision with which a microstructure with the desired shape can be fabricated is limited. Conventional thin-film processes, such as physical vapor deposition and chemical vapor deposition, require complex and difficult deposition conditions, such as high-temperature or high-vacuum maintenance. In addition, equipment management is difficult, a large number of parts and a large system are required, and large-area deposition is highly challenging. Meanwhile, in the case of IJP technology, it is feasible to deposit high-quality nanoscale thin films relatively conveniently without requiring vacuum or temperature maintenance. Furthermore, they can be manufactured over large areas. IJP can be used to conveniently fabricate various patterns in the desired shape without masking or lithography. Moreover, it can precisely control the concentration and combination of printing inks to produce thin films with desired material compositions and microstructures. We successfully fabricated perovskite-type PBSCF cathodes for PCFCs using thermal inkjet printing (T-IJP) on a BaZrxCe0.8-xY0.1Yb0.1O3-δ electrolyte using an inexpensive desktop printer. Ceramic ink solutions were formulated using PBSCF nanopowder as a solid material and dispersed in anhydrous ethanol/propylene glycol methyl ether (PGME)-based solvents. The ink properties were improved by adding various polymers such as surfactants and dispersants. Printability was verified by analyzing the viscosity, surface tension, and particle size of the pigments. The shape and microstructure of the PBSCF cathode layer were successfully adjusted by controlling the number of printing cycles and grayscale value (color level) using commercial printing software. We verified the tendency of these specimens by observing the images using a scanning electron microscope (SEM) equipped with energy dispersive spectra. We also conducted performance evaluations and electrochemical impedance spectroscopy (EIS). Finally, we obtained an optimized PBSCF cathode (G-80) with adequate thickness and a favorable number of pores and cracks. The samples had identical thicknesses of 6–7 μm. This enabled a more reliable and accurate comparison and examination of the tendencies of the specimen microstructures by using grayscale values. We enhanced the performance compared to that of our previous T-IJP work. Among the four specimens measured in this study, G-80 attained a high power output of 728 mWcm-2 in the sub-IT regime (< 600 °C). This performance is higher than that achieved in previous similar studies.
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Hertkorn, N., M. Harir, B. P. Koch, B. Michalke, P. Grill, and P. Schmitt-Kopplin. "High field NMR spectroscopy and FTICR mass spectrometry: powerful discovery tools for the molecular level characterization of marine dissolved organic matter from the South Atlantic Ocean." Biogeosciences Discussions 9, no. 1 (2012): 745–833. http://dx.doi.org/10.5194/bgd-9-745-2012.
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Abstract. Non target high resolution organic structural spectroscopy of marine dissolved organic matter (DOM) isolated on 27 November 2008 by means of solid phase extraction (SPE) from four different depths in the South Atlantic Ocean off the Angola coast (3.1° E; −17.7° S; Angola basin) provided molecular level information of complex unknowns with unprecedented coverage and resolution. The sampling was intended to represent major characteristic oceanic regimes of general significance: 5 m (FISH; near surface photic zone), 48 m (FMAX; fluorescence maximum), 200 m (upper mesopelagic zone) and 5446 m (30 m above ground). 800 MHz proton (1H) nuclear magnetic resonance (NMR) 1H NMR, spectra were least affected by fast and differential transverse NMR relaxation and produced at first similar looking, rather smooth bulk NMR envelopes reflecting intrinsic averaging from massive signal overlap. Visibly resolved NMR signatures were most abundant in surface DOM but contributed at most a few percent to the total 1H NMR integral and were mainly limited to unsaturated and singly oxygenated carbon chemical environments. The relative abundance and variance of resolved signatures between samples was maximal in the aromatic region; in particular, the aromatic resolved NMR signature of the deep ocean sample at 5446 m was considerably different from that of all other samples. When scaled to equal total NMR integral, 1H NMR spectra of the four marine DOM samples revealed considerable variance in abundance for all major chemical environments across the entire range of chemical shift. Abundance of singly oxygenated CH units and acetate derivatives declined from surface to depth whereas aliphatics and carboxyl-rich alicyclic molecules (CRAM) derived molecules increased in abundance. Surface DOM contained a remarkably lesser abundance of methyl esters than all other marine DOM, likely a consequence of photodegradation from direct exposure to sunlight. All DOM showed similar overall 13C NMR resonance envelopes typical of an intricate mixture of natural organic matter with noticeable peaks of anomerics and C-aromatics carbon whereas oxygenated aromatics and ketones were of too low abundance to result in noticeable humps at the S/N ratio provided. Integration according to major substructure regimes revealed continual increase of carboxylic acids and ketones from surface to deep marine DOM, reflecting a progressive oxygenation of marine DOM, with concomitant decline of carbohydrate-related substructures. Isolation of marine DOM by means of SPE likely discriminated against carbohydrates but produced materials with beneficial NMR relaxation properties: a substantial fraction of dissolved organic molecules present allowed the acquisition of two-dimensional NMR spectra with exceptional resolution. JRES, COSY and HMBC NMR spectra were capable to depict resolved molecular signatures of compounds exceeding a certain minimum abundance. Here, JRES spectra suffered from limited resolution whereas HMBC spectra were constrained because of limited S/N ratio. Hence, COSY NMR spectra appeared best suited to depict organic complexity in marine DOM. The intensity and number of COSY cross peaks was found maximal for sample FMAX and conformed to about 1500 molecules recognizable in variable abundance. Surface DOM (FISH) produced a slightly (~25%) lesser number of cross peaks with remarkable positional accordance to FMAX (~80% conforming COSY cross peaks were found in FISH and FMAX). With increasing water depth, progressive attenuation of COSY cross peaks was caused by fast transverse NMR relaxation of yet unknown origin. However, most of the faint COSY cross peak positions of deep water DOM conformed to those observed in the surface DOM, suggesting the presence of a numerous set of identical molecules throughout the entire ocean column even if the investigated water masses belonged to different oceanic regimes and currents. Aliphatic chemical environments of methylene (CH2) and methyl (CH3) in marine DOM were nicely discriminated in DEPT HSQC NMR spectra. Classical methyl groups terminating aliphatic chains represented only ~15% of total methyl in all marine DOM investigated. Chemical shift anisotropy from carbonyl derivatives (i.e. most likely carboxylic acids) displaced aliphatic methyl 1H NMR resonances up to δH ~1.6 ppm, indicative of alicyclic geometry which furnishes more numerous short range connectivities for any given atom pairs. A noticeable fraction of methyl (~2%) was bound to olefinic carbon. The comparatively large abundance of methyl ethers in surface marine DOM contrasted with DOM of freshwater and soil origin. The chemical diversity of carbohydrates as indicated by H2CO-groups (δC ~ 62 ± 2 ppm) and anomerics (δC ~ 102 ± 7 ppm) exceeded that of freshwater and soil DOM considerably. HSQC NMR spectra were best suited to identify chemical environments of methin carbon (CH) and enabled discrimination of olefinic and aromatic cross peaks (δC > 110 ppm) and those of doubly oxygenated carbon (δC < 110 ppm). The abundance of olefinic protons exceeded that of aromatic protons; comparison of relative HSQC cross peak integrals indicated larger abundance of olefinic carbon than aromatic carbon in all marine DOM as well. A considerable fraction of olefins seemed isolated and likely sterically constrained as judged from small nJHH couplings associated with those olefins. High S/N ratio and fair resolution of TOCSY and HSQC cross peaks enabled unprecedented depiction of sp2-hybridized carbon chemical environments in marine DOM with discrimination of isolated and conjugated olefins as well as α, β-unsaturated double bonds. However, contributions from five-membered heterocycles (furan, pyrrol and thiophene derivatives) even if very unlikely from given elemental C/N and C/S ratios and upfield proton NMR chemical shift (δH < 6.5 ppm) could not yet been ruled out entirely. In addition to classical aromatic DOM, like benzene derivatives and phenols, six-membered nitrogen heterocycles were found prominent contributors to the downfield region of proton chemical shift (δH > 8 ppm). Specifically, a rather confined HSQC cross peak at δH/δC = 8.2/164 ppm indicated a limited set of nitrogen heterocycles with several nitrogen atoms in analogy to RNA derivatives present in all four marine DOM. Appreciable amounts of extended HSQC and TOCSY cross peaks derived from various key polycyclic aromatic hydrocarbon substructures suggested the presence of previously proposed but NMR invisible thermogenic organic matter (TMOC) in marine DOM at all water depths. Eventually, olefinic unsaturation in marine DOM will be more directly traceable to ultimate biogenic precursors than aromatic unsaturation of which a substantial fraction originates from an aged material which from the beginning was subjected to complex and less specific biogeochemical reactions like thermal decomposition. The variance in molecular mass as indicated from Fourier transform ion cyclotron resonance (FTICR) mass spectra was limited and could not satisfactorily explain the observed disparity in NMR transverse relaxation of the four marine DOM samples. Likewise, the presence of metal ions in isolated marine DOM remained near constant or declined from surface to depth for important paramagnetic ions like Mn, Cr, Fe, Co, Ni and Cu. Iron in particular, a strong complexing paramagnetic ion, was found most abundant by a considerable margin in surface (FISH) marine DOM for which well resolved COSY cross peaks were observed. Hence, facile relationships between metal content of isolated DOM (which does not reflect authentic marine DOM metal content) and transverse NMR relaxation were not observed. High field (12 T) negative electrospray ionization FTICR mass spectra showed at first view rather conforming mass spectra for all four DOM samples with abundant CHO, CHNO, CHOS and CHNOS molecular series with slightly increasing numbers of mass peaks from surface to bottom DOM and similar fractions (~50%) of assigned molecular compositions throughout all DOM samples. The average mass increased from surface to bottom DOM by about 10 Dalton. The limited variance of FTICR mass spectra probably resulted from a rather inherent conformity of marine DOM at the mandatory level of intrinsic averaging provided by FTICR mass spectrometry, when many isomers unavoidably project on single nominal mass peaks. In addition, averaging from ion suppression added to the accordance observed. The proportion of CHO and CHNO molecular series increased from surface to depth whereas CHOS and especially CHNOS molecular series markedly declined. The abundance of certain aromatic CHOS compounds declined with water depth. For future studies, COSY NMR spectra appear best suited to assess organic molecular complexity of marine DOM and to define individual DOM molecules of yet unknown structure and function. Non-target organic structural spectroscopy at the level demonstrated here covered nearly all carbon present in marine DOM. The exhaustive characterization of complex unknowns in \\mbox{marine} DOM will reveal a meaningful assessment of individual marine biogeosignatures which carry the holistic memory of the oceanic water masses (Koch et al., 2011).
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Khemraj Bairwa, and Snehasis Jana. "Physical, Thermal, and Spectroscopic Characterization of Biofield Energy Treated Methyl-2-Naphthyl Ether." Environmental Analytical Chemistry 2, no. 5 (2015). https://doi.org/10.4172/2380-2391.1000162.
Full textAbstract:
Methyl-2-naphthyl ether (MNE) is an organic compound and used as the primary moiety for the synthesis of several antimicrobial and anti-inflammatory agents. This study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal, and spectroscopic properties of MNE. The study was carried out in two groups i.e., control and treated. The treated group was subjected to Mr. Trivedi’s biofield treatment. Afterward, the control and treated samples of MNE were evaluated using X-ray diffraction (XRD), surface area analyzer, differential scanning calorimetry (DSC), thermogravimetric analysis-derivative thermogravimetric analysis (TGA-DTG), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD study exhibited the decrease in average crystallite size by 30.70%. The surface area analysis showed 5.32% decrease in surface area of the treated sample with respect to the control. The DSC thermogram of treated MNE exhibited no significant change in the melting temperature; however, the latent heat of fusion was slightly increased (0.83%) after biofield treatment as compared to the control sample. The TGA analysis showed the onset temperature of thermal degradation at 158℃ in the control sample that was reduced to 124℃ after biofield treatment. The result showed about 21.52% decrease in onset temperature of thermal degradation of treated MNE as compared to the control. Similarly, the end-set temperature of thermal degradation was also reduced by 13.51% after biofield treatment with respect to the control. The FT-IR and UV spectroscopic studies did not show any changes in the wavenumber and wavelength, respectively in treated MNE with respect to the control. Overall, the XRD, surface area and thermal analysis suggest that biofield treatment has the impact on physical and thermal properties of the treated MNE as compared to the control. <strong>Source:</strong> https://www.trivedieffect.com/science/physical-thermal-and-spectroscopic-characterization-of-biofield-energy-treated-methyl-2-naphthyl-ether https://www.omicsonline.org/open-access/physical-thermal-and-spectroscopic-characterization-of-biofield-energytreated-methyl2naphthyl-ether-2380-2391-1000162.php?aid=61544
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, Gopal Nayak, Khemraj Bairwa, and Snehasis Jana. "Physical, Thermal, and Spectroscopic Characterization of Biofield Energy Treated Methyl-2-Naphthyl Ether." Environmental Analytical Chemistry 2, no. 5 (2015). https://doi.org/10.5281/zenodo.167526.
Full textAbstract:
Methyl-2-naphthyl ether (MNE) is an organic compound and used as the primary moiety for the synthesis of several antimicrobial and anti-inflammatory agents. This study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal, and spectroscopic properties of MNE. The study was carried out in two groups i.e., control and treated. The treated group was subjected to Mr. Trivedi’s biofield treatment. Afterward, the control and treated samples of MNE were evaluated using X-ray diffraction (XRD), surface area analyzer, differential scanning calorimetry (DSC), thermogravimetric analysis-derivative thermogravimetric analysis (TGA-DTG), Fourier transform infrared (FT-IR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD study exhibited the decrease in average crystallite size by 30.70%. The surface area analysis showed 5.32% decrease in surface area of the treated sample with respect to the control. The DSC thermogram of treated MNE exhibited no significant change in the melting temperature; however, the latent heat of fusion was slightly increased (0.83%) after biofield treatment as compared to the control sample. The TGA analysis showed the onset temperature of thermal degradation at 158℃ in the control sample that was reduced to 124℃ after biofield treatment. The result showed about 21.52% decrease in onset temperature of thermal degradation of treated MNE as compared to the control. Similarly, the end-set temperature of thermal degradation was also reduced by 13.51% after biofield treatment with respect to the control. The FT-IR and UV spectroscopic studies did not show any changes in the wavenumber and wavelength, respectively in treated MNE with respect to the control. Overall, the XRD, surface area and thermal analysis suggest that biofield treatment has the impact on physical and thermal properties of the treated MNE as compared to the control. https://www.trivedieffect.com/science/physical-thermal-and-spectroscopic-characterization-of-biofield-energy-treated-methyl-2-naphthyl-ether https://www.omicsonline.org/open-access/physical-thermal-and-spectroscopic-characterization-of-biofield-energytreated-methyl2naphthyl-ether-2380-2391-1000162.php?aid=61544
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Trivedi, Mahendra Kumar, Alice Branton, Dahryn Trivedi, and Gopal Nayak. "Physical, Thermal, and Spectroscopic Characterization of Biofield Energy Treated Methyl-2-Naphthyl Ether." Omics Publishing Group, September 20, 2015. https://doi.org/10.5281/zenodo.813952.
Full textAbstract:
Methyl-2-naphthyl ether (MNE) is an organic compound and used as the primary moiety for the synthesis of several antimicrobial and anti-inflammatory agents. This study was attempted to evaluate the impact of biofield energy treatment on the physical, thermal, and spectroscopic properties of MNE. The study was carried out in two groups i.e., control and treated. The treated group was subjected to Mr. Trivedi's biofield treatment. Afterward, the control and treated samples of MNE were evaluated using X-ray diffraction (XRD), surface area analyzer, differential scanning calorimetry (DSC), thermogravimetric analysis-derivative thermogravimetric analysis (TGA-DTG), Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. The XRD study exhibited the decrease in average crystallite size by 30.70%. The surface area analysis showed 5.32% decrease in surface area of the treated sample with respect to the control. The DSC thermogram of treated MNE exhibited no significant change in the melting temperature; however, the latent heat of fusion was slightly increased (0.83%) after biofield treatment as compared to the control sample. The TGA analysis showed the onset temperature of thermal degradation at 158oC in the control sample that was reduced to 124o after biofield treatment. The result showed about 21.52% decrease in onset temperature of thermal degradation of treated MNE as compared to the control. Similarly, the end-set temperature of thermal degradation was also reduced by 13.51% after biofield treatment with respect to the control. The FT-IR and UV spectroscopic studies did not show any changes in the wavenumber and wavelength, respectively in treated MNE with respect to the control. Overall, the XRD, surface area and thermal analysis suggest that biofield treatment has the impact on physical and thermal properties of the treated MNE as compared to the control. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down.
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Dosière, Marcel, Didier Villers, Mikhail G. Zolotukhin, and Michel H. J. Koch. "Comparison of the structure and thermal properties of a poly(aryl ether ketone ether ketone naphthyl ketone) with those of poly(aryl ether ketone ether ketone ketone)." e-Polymers 7, no. 1 (2007). http://dx.doi.org/10.1515/epoly.2007.7.1.1521.
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AbstractPoly(oxy-1,4-phenylene carbonyl-1,4-phenylene oxy-1,4-phenylene carbonyl-2,6-naphthalene carbonyl-1,4-phenylene) or 2,6-PEKEKNK is a polymer of the poly(aryl ether ketone) family differing from PEKEKK by the presence of a naphthyl group linked at positions 2 and 6 to the two ketone groups. It is synthesized by electrophilic precipitation polycondensation of 2,6- naphthalenedicarboxylic acid chloride with 4,4’-bis-(4-phenoxy) benzophenone in the presence of aluminium chloride. The dimensions of the orthorhombic unit cell determined from an initially amorphous, stretched film are: a = 0.778 nm, b = 0.613 nm, c = 5.52 nm. In contrast with PEKEKK no signs of polymorphism were found for 2,6 PEKEKNK. Its glass transition and melting temperatures are 20 °C and 2 °C above those of PEKEKK, respectively.
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Hedrick, J. L., W. Volksen, and D. K. Moiianty. "Imide-Aryl Ether Ketone Block Copolymers." MRS Proceedings 227 (1991). http://dx.doi.org/10.1557/proc-227-81.
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ABSTRACTImide-aryl ether ketone block copolymers were prepared and their morphology and thermal and mechanical properties investigated. The key feature of this copolymerization is the preparation of soluble aryl ether ketimine oliogmers which may be subsequently hydrolized to the aryl ether ether ketone form. A bis(amino) aryl ether ketimine oligomer was prepared via a nucleophilic aromatic substitution reaction with a molecular weight of 6,000 g/mol. The oligomer was co-reacted with 4,4′-oxydianiline (OI)A) and pyromellitic dianhydride (PMDA) diethyl ester diacyl chloride in N-methyl-2-pyrrolidone (NMP) in the presence of N-methylmorpholine. The copolymer compositions, determined by II-NMR, of the resulting amic ester based copolymers ranged from 8 to 20 wt% aryl ether ketimine content. Prior to imide formation, the ketimine moiety of the aryl ether ketimine block was hydrolyzed (p-toluene sulfonic acid) to the ketone form producing the aryl ether ether ketone block. Solutions of the copolymers were cast and cured to effect imidization, producing clear films. The copolymers displayed good thermal stability with decomposition temperatures in excess of 450°C. Multiphase morphologies were observed irrespective of the co-block type or composition.
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Zardehi‐Tabriz, Ali, Hadiseh Anavi, Yoones Ghayebzadeh, Hossein Roghani‐Mamaqani, and Mehdi Salami‐Kalajahi. "Porous Poly(Poly[Ethylene Glycol] Methyl Ether Methacrylate) Gel Polymer Electrolyte With Superior Electrochemical Properties in a High‐Performance Potassium‐Ion Battery." Battery Energy, January 30, 2025. https://doi.org/10.1002/bte2.20240096.
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ABSTRACTPotassium‐ion batteries as a suitable alternative to lithium‐ion batteries have drawn attention due to available sources of potassium, low reduction potential, better diffusion through electrolyte/electrode interface, and good ionic conductivity. Here, a photopolymerized porous gel polymer electrolyte based on poly(poly[ethylene glycol] methyl ether methacrylate) and poly(methyl methacrylate) nanoparticles shows superior thermal and electrochemical properties. After swelling in a KPF6 and EC/PC solution, the best GPE demonstrates high ionic conductivity of 2.9 × 10−2 S cm−1, potassium transference number of 0.88, and high electrochemical stability of > 6 V. This excellent electrochemical property could be related to high solvent uptake, high surface area, K+ pathway channels, low Tg, and the electron donor groups of the porous poly(poly[ethylene glycol] methyl ether methacrylate). Also, this GPE shows an initial capacity of 155 mAh g−1, an initial Coulombic efficiency of ~100%, and capacity retention of 99.9% after 100 cycles in a high current density of 5 C with high‐voltage FeFe(CN)6 as the cathode and graphite as the anode. FE‐SEM images show the ability to suppress dendrites after 100 cycles of charge–discharge at 5 C. Additionally, this GPE demonstrates 143 mAh g−1 capacity at a very high C‐rate of 10, showing its ability for use in high‐performing rechargeable potassium batteries.
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Talebi, Nafiseh, Ghasem Rezanejade Bardajee, Kourosh Kabiri, Hossein Boohendi, and Mohammad Jalal Zohuriaan Mehr. "Novel Surface Crosslinker for Superabsorbent Polymers Based on Schiff Base Reaction." Polymers for Advanced Technologies 36, no. 1 (2024). https://doi.org/10.1002/pat.70049.
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ABSTRACTSuperabsorbent surface modification significantly enhances hydrogels' structure, properties, and functionality, which cannot be directly polymerized. Over the past few decades, this modification technique has broadened the range of applications for superabsorbents in various industries. In this study, the Schiff base compound (E)‐2‐(((4‐hydroxyphenyl)imino)methyl)phenol (HPIMP) was synthesized by reacting salicylaldehyde with para‐aminophenol. The resulting diphenol compound was then transformed into bis (phenol glycidyl ether)imine (DGSB) using epichlorohydrin to create a new crosslinker. The chemical structure of the DGSB crosslinker was analyzed using FTIR and H‐NMR spectroscopies. The results from both FTIR and 1H‐NMR confirmed that the crosslinker was successfully synthesized. Then, the synthesized DGSB crosslinker (different amounts) as an external crosslinker was used to modify the sodium polyacrylate superabsorbents. The modified SAP's chemical composition and thermal stability were evaluated using FTIR and TGA methods. Various tests were applied to evaluate the SAP and modified SAP properties, including free absorption properties in water and saline solution, absorption under load, gel‐blocking properties, rheological behavior, and antibacterial properties. The storage modulus indicates that the gel strength and absorbency under load have been enhanced, reaching levels of 57,600 Pa and 24.81 g/g, respectively. It is proposed that the outer layer of the SAP particles has been altered through crosslinking. The surface alteration has also improved thermal stability and prevented unwanted gel blocking.
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Faggio, Noemi, Angela Marotta, Veronica Ambrogi, Pierfrancesco Cerruti, and Gennaro Gentile. "Fully bio-based furan/maleic anhydride epoxy resin with enhanced adhesive properties." Journal of Materials Science, April 19, 2023. http://dx.doi.org/10.1007/s10853-023-08458-8.
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AbstractEpoxy resins are widely used in a variety of application fields, thanks to their good mechanical strength, chemical resistance and adhesion to several substrates. Nowadays, the quite majority of epoxy resins are based on derivatives of bisphenol A (BPA), which poses serious health concerns. This issue is pushing the research towards suitable bio-based alternatives to this product, being furan-based epoxies very promising in this respect. In a previous work, 2,5-bis[(oxiran-2-ylmethoxy)methyl]furan (BOMF) was cured with methyl nadic anhydride (MNA), and successfully used as tinplate coating. Herein, in a view of increasing the sustainability of these epoxy resins, we have replaced MNA with maleic anhydride (MA), which can be derived from vegetable feedstocks, thus obtaining a fully bio-based epoxy resin. This latter has then been used as adhesive for carbon fiber-reinforced thermosetting plastics (CFRP). The curing process of the resin was monitored by differential scanning calorimetry (DSC) and chemo-rheological analysis. The results highlighted the significantly higher reactivity of BOMF towards MA compared to the diglycidyl ether of BPA (DGEBA). The crosslinked samples were characterized in their thermal, mechanical and adhesive properties. In comparison to DGEBA/MA and BOMF/MNA, BOMF/MA showed higher ultimate strain and slightly lower glass transition temperature, tensile modulus and ultimate strength. Interestingly, BOMF/MA displayed outstanding adhesive strength on CFRP joints, outperforming the DGEBA-based counterpart by three times. Indeed, by properly selecting the anhydride curing agent, a highly ductile fully bio-based material was developed for high performance adhesive applications. The overall results demonstrate that the properties of BOMF-based epoxy resins can be tailored to meet technical and safety requirements of downstream applications, representing a sustainable alternative to traditional systems containing DGEBA.
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Zhao, Wanting, and Lijun Chen. "Comparative study on cross-linked fluorocarbon acrylate latex." Pigment & Resin Technology, August 15, 2022. http://dx.doi.org/10.1108/prt-05-2022-0066.
Full textAbstract:
Purpose Self-crosslinked long fluorocarbon acrylate polymer latex has good hydrophobic and oleophobicity, weather resistance, aging resistance, stability and other excellent properties, which make the polymer be widely used in coatings, dyes, adhesives and other products. The purpose of this study is to prepare self-crosslinked long fluorocarbon acrylate polymer latex via semi-continuous seeded emulsion technology and carry out comparative study on two different cross-linked monomers. Design/methodology/approach Methyl methacrylate (MMA) and butyl acrylate (BA) were used as the main monomers, dodecafluoroheptyl methacrylate (DFMA) as the fluoromonomer, hydroxypropyl methacrylate (HPMA) and N-methylol acrylamide (NMA) as cross-linked monomers, and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether (ANPEO10) and 1-allyloxy-3–(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) as compound emulsifiers via the semicontinuous-seeded emulsion polymerization. Findings The properties of the polymer emulsions, which are prepared with two different cross-linked monomers, are compared and discussed, and it is concluded that HPMA is more suitable for the preparation of self-crosslinked polymer emulsions. The formula of the polymer latex is ANPEO10: DNS-86 = 1:1, and the mass ratio of the monomers used in the polymer is MMA: BA: DFMA: HPMA = 14.40:14.40:0.60:0.60. Practical implications Self-crosslinked long fluorocarbon acrylate polymer latex can be used in many fields such as coatings, dyes, adhesives and other products. Originality/value The self-crosslinked long fluorocarbon acrylate polymer latex is prepared by mixing the nonionic emulsifier ANPEO10 and the anionic emulsifier DNS-86 when potassium persulfate is used as the thermal decomposition initiator and the semicontinuous-seeded emulsion technology is adopted and the comparative study on two different cross-linked monomer is carried out, which is not reported in the open literatures.