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Artículos de revistas sobre el tema "PMMA copolymers"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 1 de febrero de 2022

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1

Hook, Thomas J., Joseph A. Gardella y Lawrence Salvati. "Multitechnique surface spectroscopic studies of plasma-modified polymers II: H2O/Ar plasma-modified polymethylmethacrylate/polymethacrylic acid copolymers". Journal of Materials Research 2, n.º 1 (febrero de 1987): 132–42. http://dx.doi.org/10.1557/jmr.1987.0132.

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Results from the x-ray photoelectron spectroscopy (XPS or ESCA), ion scattering spectroscopy (ISS or LEIS), and Fourier transform infrared spectrometry (FTIR) analyses are presented for unmodified and modified poly (methylmethacrylate)/poly (methacrylic acid) (PMMA/PMAA) copolymer films. Analyses of the unmodified PMMA/PMAA copolymer series, via ESCA, ISS, and FTIR, established the surface composition and functionality of the PMMA/PMAA copolymers before the H2O/Ar rf-plasma treatment was employed. The ESCA, ISS, and FTIR analysis of these modified PMMA/PMAA copolymers show that surface modification over a limited depth (50–200 Å) has occurred. The composition, bonding, and functionality changes of the surfaces are discussed. A two-step modification mechanism (surface reduction of the PMMA/PMAA copolymer followed by H2O adsorption) is proposed to interpret the spectroscopic results.

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2

Zhang, Xu Ming, Yu Zhang, Guo Jin y Li Li. "Surface Structure and Protein Resistance of PMMA/PS Copolymer Coatings". Applied Mechanics and Materials 268-270 (diciembre de 2012): 143–47. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.143.

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PMMA/PS copolymers were synthesized by radical polymerization techniques. And the 1H NMR results illustrate that the molar contents of PMMA are respectively 19%, 53%, 69% and 84%. The coatings of those PMMA/PS copolymers were prepared by spin-coating. The surface structures and protein resistance of copolymer coatings were investigated respectively by AFM and BSA absorption experiment. It is showed that the copolymer coating surfaces have micro-phase separation structure. Furthermore, with the increase in the PMMA content, the surface pattern changes from interpenetration network pattern to island structure that the PMMA-rich phase surrounded by the PS-rich phase. In addition, all coatings prepared in this study, especially the coating with PMMA content of 69%, have good resistance to BSA protein.

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3

Guan, Xinghua, Xiaoyan Ma, Hualong Zhou, Fang Chen y Zhiguang Li. "Synthesis and thermal decomposition kinetics of poly(methyl methacrylate)-b-poly(styrene) block copolymers". Journal of Thermoplastic Composite Materials 30, n.º 5 (14 de octubre de 2015): 691–706. http://dx.doi.org/10.1177/0892705715610406.

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Two diblock copolymers of poly(methyl methacrylate)- block-poly(styrene) with chlorine as terminal group (PMMA- b-PS-Cl) were synthesized via two-step atom transfer radical polymerization. The structures of the block copolymers were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and gel permeation chromatography. Thermal properties including glass transition temperature ( Tg) and thermal stability were studied by differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. The block copolymers of PMMA- b-PS-Cl exhibited two glass transitions, which were attributed to the Tgs of PMMA and PS segments, respectively. According to TGA, thermal decompositions of PMMA macro-initiator and PMMA- b-PS-Cl block copolymers had two stages. The weight loss ratio in the second stage was more significant than that in the first stage, which may be attributed to the separation of the halogen atom from the terminal group and the formation of a double bond. The breaking down of the backbone dominates in the second stage in which the weight loss ratio was more than 70%, represented the main stage of pyrolysis. It was found that the introduction of the PS chain remarkably enhanced the thermal stability of the copolymer, thus endowing the block copolymers high activation energy for thermal decomposition. On the other hand, the remaining two pyrolysis procedures further indicated that thermodynamic mechanism didn’t change due to the introduction of PS segments.

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4

Upadhyaya, Lakshmeesha, Mona Semsarilar, Rodrigo Fernández-Pacheco, Gema Martinez, Reyes Mallada, Isabel M. Coelhoso, Carla A. M. Portugal, João G. Crespo, André Deratani y Damien Quemener. "Nano-structured magneto-responsive membranes from block copolymers and iron oxide nanoparticles". Polymer Chemistry 8, n.º 3 (2017): 605–14. http://dx.doi.org/10.1039/c6py01870j.

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5

Zhu, Lin, Fang Chen, Xiaoyan Ma, Xiu Qiang, Zhiguang Li, Chen Dong y Duyang Zang. "Tadpole-Shaped POSS-Based Copolymers and the Aggregation Behavior at Air/Water Interface". Advances in Condensed Matter Physics 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/3787843.

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The aggregation behavior of three tadpole-shaped Polyhedral oligomeric silsesquioxane (POSS) based block copolymers using different blocks poly(methyl methacrylate) (PMMA) and poly(trifluoroethyl methacrylate) (PTFEMA) with different block sequence and ratio (POSS-PTFEMA161-b-PMMA236, POSS-PMMA277-b-PTFEMA130, and POSS-PMMA466-b-PTFEMA172) was investigated on the air-water interface. The interfacial rheology of three block copolymers was studied by surface pressure isotherm, compression modulus measurements, and compression and expansion hysteresis analysis on the Langmuir trough. The block sequence and ratio play a great role in self-assembly behavior at the interface. Based on surface pressure isotherm analysis, a thin film with low elasticity was achieved for the POSS-PTFEMA161-b-PMMA236. Moreover, for the block copolymer with same segment sequence (POSS-PMMA2-b-PTFEMA), the thin film compression capability is increased with increasing the PMMA ratio. The morphology of the deposited LB thin film was illustrated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). We observed that a thin film was composed by crater-shaped quasi-2D micelles for POSS-PTFEMA-b-PMMA, while it was proved that only flaky texture was observed for both POSS-PMMA277-b-PTFEMA130 and POSS-PMMA466-b-PTFEMA172. The thickness and area of flaky aggregates were greatly related to PMMA ratio. The different interface self-assembly structure evolution was proposed based on the interfacial rheology and thin film morphology studies.

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6

Zhou, Shi Biao, An Guo Xiao, Qing Yun Zheng, Kun Wang, Zhen Gan Chen, Wei Qing Zhang y Ai Ping Hao. "Study on Mechanical Properties of Nanocompo-Sites Prepared Using Elastomeric Copolymers and Nano-SiO₂". Advanced Materials Research 455-456 (enero de 2012): 513–19. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.513.

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Nanocomposites were obtained by mixing elastomeric copolymer and nanoSiO2 in double-screw extruder at 130-150°C, in which the elastomeric copolymer was prepared by copolymerization of poly (methyl methacrylate (PMMA) macromonomer and butyl acrylate (BA) in benzene using azobisisobutyro-nitrile (AIBN) as initiator. The results indicated that increasing the amount of PMMA, the molecular weight of PMMA and copolymers, nanosilica charged resulted in improving the tensile strength and modulus at 300% elongation of nanocomposites, on the contrary, decreasing ultimate elongation and permanent set decrease. In additions, the tensile strength and the modulus at 300% elongation of nanocomposites reached to a maximum while the mass ratio of nanoSiO2 to copolymer was 3%.

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7

Chang, Jun Jie, Hiroshi Niino, Shunsuke Chatani y Atsushi Goto. "Synthesis of block copolymers using poly(methyl methacrylate) with unsaturated chain end through kinetic studies". Polymer Chemistry 10, n.º 41 (2019): 5617–25. http://dx.doi.org/10.1039/c9py01367a.

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8

Huang, Chih-Feng y Feng-Chih Chang. "Comparison of hydrogen bonding interaction between PMMA/PMAA blends and PMMA-co-PMAA copolymers". Polymer 44, n.º 10 (mayo de 2003): 2965–74. http://dx.doi.org/10.1016/s0032-3861(03)00188-5.

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9

Gerding, Heinrich. "Fluorescein Staining of Intraocular Lenses". Klinische Monatsblätter für Augenheilkunde 235, n.º 04 (12 de marzo de 2018): 369–72. http://dx.doi.org/10.1055/s-0043-124655.

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Abstract Background Recent case reports have indicated that intraocular lenses may be discoloured by systemically or locally applied fluorescein. Since very few data are available on the susceptibility of intraocular lenses to fluorescein, an experimental survey on lens discolouration was performed. Material and Methods Intraocular lenses fabricated from polmethylmethacrylate (PMMA), silicone, hydrophobic acrylic copolymers, and hydrophilic acrylic copolymers were exposed to 10% fluorescein. Staining effects were determined by standardised quantification of light transmission. Results Intraocular lenses fabricated from PMMA, silicone, or hydrophobic acrylic copolymer did not exhibit any measurable dye uptake after exposure to fluorescein. Intensive and rapid discolouration occurred in hydrophilic acrylic intraocular lenses. The transmission of blue light was reduced by 22% after 1 second and by 74% after 10 minutes of dye exposure. Conclusions The results indicate that hydrophilic acrylic intraocular lenses develop rapid and intensive discolouration and reduced light transmission after exposure to fluorescein. Lenses fabricated from other materials (PMMA, silicone, hydrophobic acrylic copolymers) were not discoloured by fluorescein staining.

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10

Tang, Er Jun, Miao Yuan, Liang Li, Feng Bian y Di Shun Zhao. "Synthesis of Microcrystalline Cellulose Grafting Poly (methyl methacrylate) Copolymers by ATRP in 1-Allyl-3-Methylimidazolium Chloride". Advanced Materials Research 621 (diciembre de 2012): 157–61. http://dx.doi.org/10.4028/www.scientific.net/amr.621.157.

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The microcrystalline cellulose grafting polymethylmethacrylate (MCC-g-PMMA) copolymer was successfully synthesized by atom transfer radical polymerization (ATRP) using ethanediamine as ligand in Ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). The MCC-g-PMMA was characterized by FT-IR, 1H NMR, SEM and GPC spectroscopies. The results confirmed that the PMMA had been covalently bonded to cellulose backbone. The molecular weight of graft copolymers linearly increased during the polymerization and presented a low polydispersity.

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11

Ni, Henmei, Junxiu Liu, Kai Shi, Min Wu, Yadong Yang y Lijuan Zhang. "PMAA-based RAFT dispersion polymerization of MMA in ethanol: conductivity, block length and self-assembly". RSC Advances 6, n.º 63 (2016): 58218–25. http://dx.doi.org/10.1039/c6ra09895a.

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12

Kim, Do Hyun, Min Su Park, Hyung Hee Cho, Jung Tae Park y Jong Hak Kim. "Synthesis of organized mesoporous metal oxide films templated by amphiphilic PVA–PMMA comb copolymer". RSC Advances 6, n.º 72 (2016): 67849–57. http://dx.doi.org/10.1039/c6ra13844f.

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We present a synthesis of organized mesoporous metal oxide films with high porosity and good interconnectivity using an amphiphilic PVA–PMMA comb copolymer which can be a promising template as an alternative to conventional block copolymers.

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13

Eric, Ofosu-Twum, Yougen Chen, Kenji Takada, Shin-ichiro Sato, Toshifumi Satoh y Toyoji Kakuchi. "Synthesis of AB block and A2B2 and A3B3 miktoarm star-shaped copolymers using ω-end-functionalized poly(methyl methacrylate) with a hydroxyl group prepared by organocatalyzed group transfer polymerization". Polymer Chemistry 6, n.º 45 (2015): 7841–50. http://dx.doi.org/10.1039/c5py01112d.

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14

Chen, Dan, Fupeng Zhu, Tingting Zhou, Mingyao Zhang y Huixuan Zhang. "The performance and morphology of PMMA/SAN/ABS blends". Journal of Polymer Engineering 36, n.º 3 (1 de abril de 2016): 321–27. http://dx.doi.org/10.1515/polyeng-2014-0209.

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Abstract Acrylonitrile-butadiene-styrene (ABS) graft copolymers were synthesized via seeded emulsion polymerization techniques by grafting styrene (St) and acrylonitrile (AN) on polybutadiene (PB) particles. Poly (methyl methacrylate) (PMMA)/styrene-acrylonitrile (SAN)/ABS blends were prepared by melt blending ABS graft copolymers with PMMA and SAN resins. The properties, morphology and grafted chains behaviors of PMMA/SAN/ABS blends were investigated. The results showed that with the increase of the ratio of PMMA/SAN, the toughness of PMMA/SAN/ABS blends slightly decreased, the transmittance first increased and then decreased, and tensile strength was not dependent on the ratio of PMMA/SAN. The evolution of impact strength of the blends was similar with the tendency of grafted degree (GD) with the increase of cumene hydroperoxide (CHP) and tert-dodecyl mercaptan (TDDM). From transmission electron microscopy (TEM), it was found that ABS graft copolymers were uniformly dispersed in PMMA/SAN matrix.

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15

Jiang, Sai Hua, Siu Ming Lo y Yuan Hu. "Enhanced Thermal Stability and Flame Retardancy of a Novel Transparent Poly(Methyl Methacrylate)-Based Copolymer". Advanced Materials Research 911 (marzo de 2014): 423–27. http://dx.doi.org/10.4028/www.scientific.net/amr.911.423.

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A novel poly (methyl methacrylate) (PMMA) based copolymer was synthesized by bulk copolymerization of methyl methacrylate (MMA) and a phosphorus-containing monomer, acryloxyethyl phenoxy phosphorodiethyl amidate (AEPPA). The chemical structure of AEPPA was confirmed by FTIR,1H NMR and31P NMR. The structure of copolymers was characterized using FTIR. TGA results indicate that the thermal stability of copolymers was remarkably enhanced with the addition of APEEA. LOI and MCC results suggest that the flame retardancy of copolymers was also improved. Detailed flame-retardant mechanism is proposed. The char formation during degradation caused by APEEA plays a key role in the property improvements.

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16

Winey, Karen I. y Mary E. Galvin. "TEM and image analysis to quantitatively describe the phase behavior in copolymer/homopolymer/homopolymer blends: Effect of the copolymer sequence distribution". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 de agosto de 1993): 896–97. http://dx.doi.org/10.1017/s0424820100150319.

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Polymers are typically immiscible with one another, that is phase separated, in the absence of specific favorable intermolecular interactions, because the combinatorial entropy of mixing is small. Copolymers, polymer molecules containing more than one type of monomer unit, are frequently used to induce miscibility in homopolymer mixtures. Extensive work has previously established the importance of the copolymer composition, though the sequence of monomers within the copolymer has received less attention. Copolymers with random and with alternating sequences of monomers have been synthesized and mixed with homopolymers to evaluate the importance of the sequence distribution on blend miscibility. Blend miscibility determinations using differential scanning calorimetry and visual inspection can be erroneous when the glass transition temperatures of the phases are similar or the domains are small compared to the wavelength of light. Thus, we have used transmission electron microscopy to study the phase behavior of these polymer blends.Blend samples (∼30 mg) of poly(styrene-co-methyl methacrylate) (PS-PMMA), homopolystyrene (PS), homopoly(methyl methacrylate) (PMMA) were prepared by casting from tetrahydrofuran and annealing at 150°C for 7 days.

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17

Borsetto, F., B. Kosmala, T. G. Fitzgerald, Matthew T. Shaw, J. Patterson, P. Rapposelli, J. M. O´Callaghan, J. D. Holmes y Michael A. Morris. "Polystyrene-Polymethylmethacrylate Block Copolymers for Lithographically Assisted Bottom-Up Assembly of Nanostructures". Materials Science Forum 555 (septiembre de 2007): 29–34. http://dx.doi.org/10.4028/www.scientific.net/msf.555.29.

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Polystyrene-polymethylmethacrylate (PS-PMMA) block copolymers are well known to exhibit microphase separation to form a series of regular structures with local periodic arrangements of the blocks. By developing films of PS-PMMA within topographically patterned silicon (100) substrates (with photolithographically defined rectangular channels of depth 60 nm and widths 166 – 433 nm) these irregular arrangements form highly periodic structures where the features are parallel to the side walls of the channels. However, the use of silicon substrates leads to problems in processing of these films. PS-PMMA does not wet the surface, and this results in island formation on flat substrates. On channel etched substrates this phenomena ensures that the thickness of the films is irregular and poorly defined alignment is seen. Detailed considerations of this polymer system suggest that feature sizes below 25 nm are not realisable. The results suggest other copolymer systems should be studied.

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18

Sakellariou, P., G. C. Eastmond y I. S. Miles. "Interfacial activity of polycarbonate/PMMA graft copolymers in polycarbonate/PMMA blends: effect of copolymer concentration". Polymer 32, n.º 13 (enero de 1991): 2351–62. http://dx.doi.org/10.1016/0032-3861(91)90073-r.

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19

Tham, Do Quang, Tran Thi Mai, Thai Hoang, Nguyen Thi Thu Trang, Nguyen Thuy Chinh y Dam Xuan Thang. "PREPARATION AND FTIR STUDIES OF PMMA/PVC POLYMER BLENDS, PVC-g-PMMA GRAFT COPOLYMERS AND EVALUATING GRAFT CONTENT". Vietnam Journal of Science and Technology 57, n.º 1 (18 de febrero de 2019): 48. http://dx.doi.org/10.15625/2525-2518/57/1/12682.

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This study presents the qualitative and quantitative analyses of Fourier Transform Infrared (FTIR) spectra of poly(methyl methacrylate)/poly(vinyl chloride) blends (PMMA/PVC), as well as PVC-g-PMMA graft copolymers. Graft copolymerizations of methyl mathacrylate (MMA) onto PVC macromolecules were carried out mixture of cyclohexanone/N,N-dimethylformamide as solvents, dibenzoyl peroxide as initiator and nitrogen medium. FTIR spectra of PMMA/PVC blends showed that there were molecular interactions between C=O groups of PMMA and C-Cl groups of PVC. Assignments of infrared absorption bands for specific groups of PMMA/PVC blends have been contributed. Using regression method, linear calibration curve between PMMA mole content and peak areas of C=O groups in FTIR spectra of the blends has been found when C=O peak areas were multiplied by an appropriate factor. PMMA grafted content and total PMMA formed content in PVC-g-PMMA graft copolymers have been evaluated. The results showed that grafted PMMA content was increased since PVC was initiatly dechlorinated by NaOH solution. The grafted PMMA content and total formed PMMA content were 5.05 wt.% and 11.25 wt.% respectively when MMA monomers were grafted onto neat PVC and modified PVC molecules.

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20

Kretzschmar, Hendrik, Ernst-J. Donth, Heino Tanneberger, Dinesh Garg y Siegfried Höring. "Crystallization behaviour of pmma-b-peo-b-pmma triblock copolymers". Thermochimica Acta 93 (septiembre de 1985): 151–54. http://dx.doi.org/10.1016/0040-6031(85)85039-5.

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21

Lalande, Laure, Christopher J. G. Plummer, Jan-Anders E. Månson y Pierre Gérard. "Microdeformation mechanisms in rubber toughened PMMA and PMMA-based copolymers". Engineering Fracture Mechanics 73, n.º 16 (noviembre de 2006): 2413–26. http://dx.doi.org/10.1016/j.engfracmech.2006.05.014.

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22

Chang, Jun Jie, Longqiang Xiao, Chen-Gang Wang, Hiroshi Niino, Shunsuke Chatani y Atsushi Goto. "Use of poly(methyl methacrylate) with an unsaturated chain end as a macroinitiator precursor in organocatalyzed living radical block polymerization". Polymer Chemistry 9, n.º 39 (2018): 4848–55. http://dx.doi.org/10.1039/c8py01066h.

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23

Göktaş, Melahat y Guodong Deng. "Synthesis of Poly(methyl methacrylate)-b-poly(N-isopropylacrylamide) Block Copolymer by Redox Polymerization and Atom Transfer Radical Polymerization". Indonesian Journal of Chemistry 18, n.º 3 (30 de agosto de 2018): 537. http://dx.doi.org/10.22146/ijc.28645.

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Poly(methyl methacrylate)-b-poly(N-isopropylacrylamide) [PMMA-b-PNIPAM] block copolymers were obtained by a combination of redox polymerization and atom transfer radical polymerization (ATRP) methods in two steps. For this purpose, PMMA macroinitator (ATRP-macroinitiator) was synthesized by redox polymerization of methyl methacrylate and 3-bromo-1-propanol using Ce(NH4)2(NO3)6 as a catalyst. The synthesis of PMMA-b-PNIPAM block copolymers was carried out by means of ATRP of ATRP-macroinitiator and NIPAM at 60 °C. The block copolymers were obtained in high yield and high molecular weight. The characterization of products was accomplished by using multi instruments and methods such as nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis.

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24

ZHU, HUI, PENG CHEN, RU XIA, JIASHENG QIAN, JIBIN MIAO, BIN YANG y LIFEN SU. "EFFECT OF MACROMOLECULAR COUPLING AGENT PMMA-b-PVTES ON STABILIZING NANO-Si3N4". Nano 09, n.º 08 (diciembre de 2014): 1450095. http://dx.doi.org/10.1142/s1793292014500957.

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Poly(methyl methacrylate)-b-poly(vinyltriethoxysilane) (PMMA-b-PVTES) are synthesized using atom transfer radical polymerization (ATRP) and used as macromolecular coupling agents to modify silicon nitride nanoparticles (nano- Si 3 N 4). The chemical composition of copolymers PMMA-b-PVTES and modified nano- Si 3 N 4 are confirmed by various characterization techniques. The modified nano- Si 3 N 4 shows excellent hydrophobic nature, which make nanoparticles (NPs) stably disperse in organic solvent. Transmission electron microscope (TEM), particle size testing, contact angle measuring and sedimentation experiment are employed to examine the dispersion of modified nano- Si 3 N 4 in chloroform. By comparing the effects of copolymers with varied number-average molecular weight (Mn) and block length ratio on stabilizing nano- Si 3 N 4, we discussed the mechanism of macromolecular coupling agent stabilizing NPs. In our experiments, the copolymer PMMA88-b-PVTES17 is found to be the most effective macromolecular coupling agent for stabilizing nano- Si 3 N 4.

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25

Qudsieh, Isam Yassin. "BIODEGRADATION BEHAVIOR OF POLY(METHYL METHACRYLATE) GRAFTED SAGO STARCH BIOPOLYMER". IIUM Engineering Journal 8, n.º 2 (29 de septiembre de 2010): 37–45. http://dx.doi.org/10.31436/iiumej.v8i2.91.

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The graft copolymerization of poly(methyl methacrylate) (PMMA) onto sago starch (sago starch-g-PMMA) was carried out using ceric ammonium nitrate (CAN) as an initiator. PMMA was grafted onto sago starch using CAN as an initiator under nitrogen gas atmosphere. The maximum percentage of grafting (%G) was determined to be 246% at the optimum conditions. The copolymers produced were characterized by Fourier Transform Infrared Spectrophotometry (FTIR), The FTIR spectra of the copolymers clearly indicated the presence of characteristic peaks of PMMA and sago starch, which suggested that PMMA had been successfully grafted on the sago starch. Biodegradability studies of sago starch-g-PMMA and sago starch were carried out by ?-amylase enzyme. Maximum biodegradation of the biopolymer was achieved after 3 days of incubation, while for the product was 7 days. The maximum production of glucose was achieved when the concentration of -amylase was 50 ppm.

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26

Palacio, Manuel L. B., Scott R. Schricker y Bharat Bhushan. "Bioadhesion of various proteins on random, diblock and triblock copolymer surfaces and the effect of pH conditions". Journal of The Royal Society Interface 8, n.º 58 (8 de diciembre de 2010): 630–40. http://dx.doi.org/10.1098/rsif.2010.0557.

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The adhesive interactions of block copolymers composed of poly(methyl methacrylate) (PMMA)/poly(acrylic acid) (PAA) and poly(methyl methacrylate)/poly(2-hydroxyethyl methacrylate) (PHEMA) with the proteins fibronectin, bovine serum albumin and collagen were studied by atomic force microscopy. Adhesion experiments were performed both at physiological pH and at a slightly more acidic condition (pH 6.2) to model polymer–protein interactions under inflammatory or infectious conditions. The PMMA/PAA block copolymers were found to be more sensitive to the buffer environment than PMMA/PHEMA owing to electrostatic interactions between the ionized acrylate groups and the proteins. It was found that random, diblock and triblock copolymers exhibit distinct adhesion profiles although their chemical compositions are identical. This implies that biomaterial nanomorphology can be used to control protein–polymer interactions and potentially cell adhesion.

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27

Macit, Hulya y Baki Hazer. "Synthesis of PMMA-PTHF-PMMA and PMMA-PTHF-PST linear and star block copolymers". Journal of Applied Polymer Science 93, n.º 1 (2004): 219–26. http://dx.doi.org/10.1002/app.20455.

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28

Courbaron Gilbert, Anne-Claude, Nour-Eddine El Bounia, Eve Péré, Laurent Billon y Christophe Derail. "Dispersion Improvement of Carbon Nanotubes in Epoxy Resin Using Amphiphilic Block Copolymers". Advanced Materials Research 112 (mayo de 2010): 29–36. http://dx.doi.org/10.4028/www.scientific.net/amr.112.29.

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Interface between Carbon NanoTubes (CNT) and epoxy matrix is admitted to play an important role in the dispersion quality and in the mechanical stress transfer. To improve the interfacial adhesion, we propose to chemically graft molecules onto CNT surface. To achieve this chemical modification, a controlled radical polymerization, named Nitroxide Mediated Polymerization NMP, is used to synthesize a diblock copolymer based on Acrylic Acid (PAA block) and Methyl MethAcrylate (PMMA block). In the present paper, this polymerization is performed “in situ”. The PAA block presents a good affinity with the CNT which enable grafting. The PMMA miscibility with epoxy is expected to give a good adhesion - between the CNT and the matrix - and to bring a better dispersion. In order to compare the chemical modification and the physical adsorption of the copolymers onto CNT dispersion, the same block copolymer was synthesized with and without CNT. The copolymer synthesis was controlled and characterized by different methods as NMR 1H (conversion and composition), SEC (molecular weight) and TGA (grafting density). We show that the better dispersion quality and better physical properties have been obtained with grafted CNT.

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29

Martínez-Cornejo, Vanessa, Joaquin Velázquez-Roblero, Veronica Rosiles-González, Monica Correa-Duran, Alejandro Avila-Ortega, Emanuel Hernández-Núñez, Ronan Le Lagadec y Maria Ortencia González-Díaz. "Synthesis of Poly(2-Acrylamido-2-Methylpropane Sulfonic Acid) and its Block Copolymers with Methyl Methacrylate and 2-Hydroxyethyl Methacrylate by Quasiliving Radical Polymerization Catalyzed by a Cyclometalated Ruthenium(II) Complex". Polymers 12, n.º 8 (27 de julio de 2020): 1663. http://dx.doi.org/10.3390/polym12081663.

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The first example of quasiliving radical polymerization and copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) without previous protection of its strong acid groups catalyzed by [Ru(o-C6H4-2-py)(phen)(MeCN)2]PF6 complex is reported. Nuclear magnetic resonance (RMN) and gel permeation chromatography (GPC) confirmed the diblock structure of the sulfonated copolymers. The poly(2-acryloamido-2-methylpropanesulfonic acid)-b-poly(methyl methacrylate) (PAMPS-b-PMMA) and poly(2-acryloamido-2-methylpropanesulfonic acid)-b-poly(2-hydroxyethylmethacrylate) (PAMPS-b-PHEMA) copolymers obtained are highly soluble in organic solvents and present good film-forming ability. The ion exchange capacity (IEC) of the copolymer membranes is reported. PAMPS-b-PHEMA presents the highest IEC value (3.35 mmol H+/g), but previous crosslinking of the membrane was necessary to prevent it from dissolving in aqueous solution. PAMPS-b-PMMA exhibited IEC values in the range of 0.58–1.21 mmol H+/g and it was soluble in methanol and dichloromethane and insoluble in water. These results are well correlated with both the increase in molar composition of PAMPS and the second block included in the copolymer. Thus, the proper combination of PAMPS block copolymer with hydrophilic or hydrophobic monomers will allow fine-tuning of the physical properties of the materials and may lead to many potential applications, such as polyelectrolyte membrane fuel cells or catalytic membranes for biodiesel production.

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30

Zhang, Yan Hong, Yan Wang, Xian Chao Kong y Dong Mei Zhao. "The Polarity of poly(methyl methacrylate) Copolymers". Applied Mechanics and Materials 687-691 (noviembre de 2014): 4411–14. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.4411.

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Poly (methyl methacrylate) (PMMA) is known as one of the common transparent polymer materials. In this work, pure poly (methyl methacrylate), methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-styrene copolymer was synthesized by bulk polymerization based on the mechanism of free radical polymerization to observe the polarity change of the PMMA after introducing styrene and acrylonitrile monomers. Meanwhile the glass transition temperature, hardness, contact angle and color distribution of the copolymer were measured through polymer temperature deformation analysis experiment, hardness and contact angle measuring instrument.

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31

Al-Odayni, Abdel-Basit, Waseem Sharaf Saeed, Ahmed Yacine Badjah Hadj Ahmed, Ali Alrahlah, Abdullah Al-Kahtani y Taieb Aouak. "New Monomer Based on Eugenol Methacrylate, Synthesis, Polymerization and Copolymerization with Methyl Methacrylate–Characterization and Thermal Properties". Polymers 12, n.º 1 (8 de enero de 2020): 160. http://dx.doi.org/10.3390/polym12010160.

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Poly(eugenyl-2-hydroxypropyl methacrylate) (PEUGMA), poly(methyl methacrylate) (PMMA) and poly(eugenyl-2-hydroxypropyl methacrylate-co-methyl methacrylate) (PEUGMA-co-MMA) were synthesized by a free radical polymerization route in the presence of azobisisobutyronitrile. EUGMA was synthesized by etherification of the eugenol phenolic hydroxyl group with glycidyl methacrylate. Polymers and copolymers were characterized using size exclusion chromatography, Fourier transform infrared, and nuclear magnetic resonance. The effects of the encumbering substituent on the thermal behavior of the polymers and copolymers were studied by differential scanning calorimetry, thermogravimetry (TG) and direct analysis, using real-time, time-of-flight mass spectroscopy (DART-ToF-MS) methods. The results obtained revealed that for PEUGMA, the average molecular weight was 1.08 × 105, and increased slowly with the decrease in the EUGMA content in the copolymer. The order of the distribution of dyads comonomer units in the copolymer chains estimated by the Igarashi method based on the reactivity ratio does reveal a random distribution with a tendency toward alternation. The glass transition temperature of PEUGMA (46 °C) increased with the MMA content in the copolymer, and those of the copolymer fit well with the Johnston’s linearized expression. The TG analysis of pure PEUGMA revealed a significantly high thermal stability compared to that of PMMA. During its degradation, the preliminary decomposition was at 340 °C, and decreased as the MMA units increased in the copolymer. The DART-ToF-MS analysis revealed that the isothermal decomposition of PEUGMA led to a regeneration of raw materials such as EUGMA, GMA and EUG, in which the maximum amount was achieved at 450 °C.

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32

Theato, Patrick y Daniel Klinger. "Synthesis of Photoreactive Block Copolymers Based on 1-Iminopyridinium Ylides". Australian Journal of Chemistry 63, n.º 8 (2010): 1164. http://dx.doi.org/10.1071/ch10079.

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Two photoreactive pyridinium ylide containing monomers, {[2-(metacryloyloxy)ethoxy]carbonyl}(pyridinium-1-yl)azanide (M1) and pyridinium-1-yl-(4-vinylbenzoyl)azanide (M2), were synthesized. Both monomers were polymerized under controlled radical polymerization conditions, i.e. reversible addition–fragmentation chain transfer polymerization (M1 and M2) and nitroxide-mediated polymerization (M2). Further block copolymers PMMA-b-PM1 and PS-b-PM2 were successfully synthesized and their molecular weight, Mn, and block ratio could be determined by 1H NMR analysis, thereby opening the synthetic possibilities of photoreactive ylides in block copolymer syntheses.

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33

Nguyen, Thi Nhan, Hieu Nguyen Duy, Dung Tran Anh, Thuong Nghiem Thi, Thu Ha Nguyen, Nam Nguyen Van, Tung Tran Quang, Tung Nguyen Huy y Thuy Tran Thi. "Improvement of Thermal and Mechanical Properties of Vietnam Deproteinized Natural Rubber via Graft Copolymerization with Methyl Methacrylate". International Journal of Polymer Science 2020 (14 de julio de 2020): 1–11. http://dx.doi.org/10.1155/2020/9037827.

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In this study, we investigated the improvement of the thermal and mechanical properties of Vietnam deproteinized natural rubber (DPNR) via graft copolymerization of methyl methacrylate (MMA). The graft copolymerization was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) and tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds and initiator concentration of 6.6×10−5 mol/g-rubber, the highest grafting efficiency and conversion were achieved at MMA of 15 wt.% per kg of rubber, 68% and 90%, respectively. The structure of grafted copolymers was characterized by 1H NMR, FTIR-ATR, and GPC, and thermal properties were investigated through DSC and TGA measurements. These showed that graft copolymers were more stable and rigid than DPNR. Storage modulus (G′) of graft copolymer was found to double that of DPNR, which contributed to the formation of graft copolymer. After sulfur vulcanization, the mechanical properties of DPNR-graft-PMMA, such as tensile strength, tear strength, and hardness, were improved significantly. Curing behaviors of the graft copolymers were found to be remarkably better than virgin DPNR.

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34

Pasch, Peter, Julian Papadopoulos, Andreas Goralczyk, Marc L. Hofer, Monir Tabatabai, Thomas J. J. Müller y Laura Hartmann. "Highly Fluorescent Merocyanine and Cyanine PMMA Copolymers". Macromolecular Rapid Communications 39, n.º 15 (20 de junio de 2018): 1800277. http://dx.doi.org/10.1002/marc.201800277.

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35

Reglero, Jose Antonio, Philippe Viot y Michel Dumon. "Foaming of amorphous polymers and blends in supercritical CO2: Solubility versus block copolymers addition". Journal of Cellular Plastics 47, n.º 6 (noviembre de 2011): 535–48. http://dx.doi.org/10.1177/0021955x11415925.

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Supercritical CO2 (scCO2) is used as a medium for foaming amorphous polymers. Astudy of the solubility of supercritical CO2 in several amorphous polymers (PS andPMMA) and blends is performed, followed by an investigation of the foaming behavior of the polymer–gas systems. Nano-structuring triblock copolymers (styrene-co- butadiene-co-methylmethacrylate SBM and methylmethacrylate-co-butylacrylate-co- methylmethacrylate MAM) were blended as additives to PS or PMMA by extrusion. The addition of these triblock copolymers results in an important weight gain ratio of gas in a wide range of temperatures (from 25 to 80°C), relating this weight gain ratio to the foaming behavior of the blends (CO2 is preferentially located in the micro or nano-domains issued from the structuration of the block copolymer). Foaming is carried out in a batch one-step scCO2 process, keeping constant the saturation pressure and depressurization rate (300 bar and 60 bar/min, respectively). Influence of saturation temperature (25–85 °C) on the final porous structure is shown. In spite of the influence of the terpolymer on the weight gain ratio, the structuration is believed to provide a good control of microcellular foams in PS and PMMA.

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36

Kai, Dan, Shan Jiang, Zhi Wei Low y Xian Jun Loh. "Engineering highly stretchable lignin-based electrospun nanofibers for potential biomedical applications". Journal of Materials Chemistry B 3, n.º 30 (2015): 6194–204. http://dx.doi.org/10.1039/c5tb00765h.

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37

Mu, Dan, Jian-Quan Li y Sheng-Yu Feng. "Mesoscale simulation of the formation and dynamics of lipid-structured poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers". Physical Chemistry Chemical Physics 17, n.º 19 (2015): 12492–99. http://dx.doi.org/10.1039/c5cp00561b.

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38

Sun, Jiang Ping, Yang Zhang, Jian Li, Chen Yi Wang y Qiang Ren. "Synthesis of PBMA-b-PGMA Block Copolymers via ICAR ATRP and their Application in Polymer/Titanium Dioxide Hybrid Materials". Journal of Nano Research 41 (mayo de 2016): 63–73. http://dx.doi.org/10.4028/www.scientific.net/jnanor.41.63.

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Well-defined functional block copolymers, polybutyl methacrylate-b-polyglycidyl methacrylate (PBMA-b-PGMA), were successfully synthesized via initiators for continuous activator regeneration atom transfer radical polymerization ( ICAR ATRP) with pentamethyldiethylene-triamine (PMDETA) as a ligand and copper bromide (CuBr2 ) as a catalyst with concentration of 500 ppm. The PBMA-b-PGMA grafted with titanium dioxide (TiO2 ) nanoparticles was obtained through the reaction between the epoxide on the PGMA segment and amine group on the surface of modified TiO2 nanoparticles. Results showed that the PBMA-b-PGMA block copolymer with about same length of PBMA and PGMA segment could get highest graft ratio and about 17%wt TiO2 nanoparticles were successfully grafted onto the PBMA-b-PGMA block copolymer. The sizes of the PBMA-b-PGMA grafted nanoparticles were about 74 nm in ethyl acetate. The PBMA-b-PGMA grafted TiO2 nanoparticles showed very good dispensability in organic solvent (e.g. ethyl acetate) and polymer matrix. Polymethyl methacrylate (PMMA) containing 0.5%wt PBMA-b-PGMA grafted TiO2 nanoparticles showed strong absorption at about 300 nm and good transparency in visible region, which was attributed to good dispensability of PBMA-b-PGMA grafted TiO2 nanoparticles in PMMA matrix.

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39

Koo, Jae-Sun, Peter G. R. Smith, Richard B. Williams, Christos Riziotis y Martin C. Grossel. "UV written waveguides using crosslinkable PMMA-based copolymers". Optical Materials 23, n.º 3-4 (septiembre de 2003): 583–92. http://dx.doi.org/10.1016/s0925-3467(03)00025-9.

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40

Pan, Aizhao, Shao Yang, Ling He y Xiang Zhao. "Star-shaped POSS diblock copolymers and their self-assembled films". RSC Adv. 4, n.º 53 (2014): 27857–66. http://dx.doi.org/10.1039/c4ra03337j.

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41

Lu, Yi-Syuan, Chia-Yu Yu, Yung-Chih Lin y Shiao-Wei Kuo. "Hydrogen bonding strength of diblock copolymers affects the self-assembled structures with octa-functionalized phenol POSS nanoparticles". Soft Matter 12, n.º 8 (2016): 2288–300. http://dx.doi.org/10.1039/c5sm02959g.

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42

Chen, Yulin y Zhibin Guan. "Multivalent hydrogen bonding block copolymers self-assemble into strong and tough self-healing materials". Chem. Commun. 50, n.º 74 (2014): 10868–70. http://dx.doi.org/10.1039/c4cc03168g.

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ABA triblock copolymers with glassy PMMA middle blocks and dynamic hydrogen bonding terminal blocks self-assemble into nanocomposites having an excellent combination of mechanical strength and self-healing capability.

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43

I. Waisi, Basma. "Carbonized Copolymers Nonwoven Nanofibers Composite: Surface Morphology and Fibers Orientation". Iraqi Journal of Chemical and Petroleum Engineering 20, n.º 2 (30 de junio de 2019): 11–15. http://dx.doi.org/10.31699/ijcpe.2019.2.2.

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Carbonized nonwoven nanofibers composite were fabricated using the electrospinning method of a polymeric solution composite followed by heat treatment including stabilization and calcination steps. The spun polymeric solution was a binary polymer mixture/organic solvent. In this study, two types of polymers (Polymethylmethacrylate (PMMA) and Polyethylene glycol (PEG)) were used separately as a copolymer with the base polymer (Polyacrylonitrile (PAN)) to prepare a binary polymer mixture in a mixing ratio of 50:50. The prepared precursor solutions were used to prepare the precursor nanofibers composite (PAN: PMMA) and (PAN: PEG). The fabricated precursors nonwoven fibers composite were stabilized and carbonized to produce carbon nonwoven nanofibers composite. The effect of the combined polymer type on the fiber size, fiber size distribution, and surface morphology of the prepared nonwoven nanofibers was studied. The nonwoven fibers orientation and surface morphology were characterized using field emission scanning electron microscope (FESEM). In addition, ImageJ software has been used to calculate the fiber size and fiber size distribution. Here, the obvious effect of the copolymer type on the surface morphology, fiber size, and fiber orientation has been demonstrated. Using a copolymer with PAN polymer led to increasing the fiber size. The carbonized nanofibers composite prepared using PEG polymer as a copolymer was more ordered fibers in comparison with the fiber orientation of carbon nanofibers based on pure PAN. In contrast of that, using PMMA as a copolymer resulted curly carbonized nonwoven nanofiber composite.

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44

Appold, Michael, Cristina Mari, Christina Lederle, Johannes Elbert, Claudia Schmidt, Ingo Ott, Bernd Stühn, Gilles Gasser y Markus Gallei. "Multi-stimuli responsive block copolymers as a smart release platform for a polypyridyl ruthenium complex". Polymer Chemistry 8, n.º 5 (2017): 890–900. http://dx.doi.org/10.1039/c6py02026g.

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An efficient protocol for the preparation of poly(N,N-dimethylaminoethyl methacrylate)(PDMAEMA)-based multi-stimuli responsive block copolymers (BCPs) with poly(methyl methacrylate) (PMMA)viaanionic polymerization protocols is presented.

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45

Moolsin, Supat, Nattawud Saksayamkul y Adul Na Wichien. "Natural rubber grafted poly(methyl methacrylate) as compatibilizer in 50/50 natural rubber/nitrile rubber blend". Journal of Elastomers & Plastics 49, n.º 5 (7 de octubre de 2016): 422–39. http://dx.doi.org/10.1177/0095244316671021.

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The effects of graft copolymers applied as compatibilizers for natural rubber/nitrile rubber (NR/NBR) blends at 50/50 (w/w) on cure characteristics, mechanical properties, thermal properties, oil resistance, and morphology were investigated. The graft copolymers of methyl methacrylate (MMA) onto NR initiated by benzoyl peroxide (NR- g-PMMA<BPO>) and by potassium persulfate (NR- g-PMMA<PPS>) under emulsion polymerization were synthesized and used to compatibilize the blends. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. NR was blended with NBR via a two-roll mill at 70°C under the compatibilizer loading ranging from 0 to 10 parts per hundred of rubber (phr). The results showed that the tensile property and tear strength of the blends increased with the increasing amount of NR- g-PMMA<BPO> as a compatibilizer. Thermal aging determined in terms of tensile properties exhibited the smaller difference between before and after aging in an oven with the increasing compatibilizer loading. The morphology of the compatibilized NR/NBR vulcanizates was investigated by scanning electron microscopy of the tensile fracture surfaces, which exhibited the improvement of interfacial adhesion between the two rubber phases. The thermal properties of compatibilized NR/NBR vulcanizates were reported in terms of a glass transition temperature under differential scanning calorimetry and dynamic mechanical analysis. The incorporation of an appropriate amount of the compatibilizer into the blends apparently improved the oil resistance of NR. Among them, the blend filled with 7.5 phr of NR- g-PMMA<BPO> showed the lowest volume change in IRM 903 oil.

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46

Chen, Quan, Wenjing Lin, Haiying Wang, Jufang Wang y Lijuan Zhang. "PDEAEMA-based pH-sensitive amphiphilic pentablock copolymers for controlled anticancer drug delivery". RSC Advances 6, n.º 72 (2016): 68018–27. http://dx.doi.org/10.1039/c6ra10757e.

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The synthesis of a series of PDEAEMA-based pH-sensitive amphiphilic pentablock copolymers PEG-b-(PDEAEMA-b-PMMA)₂ with different compositions proceeded via the combination of a bromination reaction andARGET ATRP.

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47

Ding, Jin, Zhen Ming Yue, Jiao Sun, Ji Cui Zhou y Jun Gao. "Effect of ABS/PMMA/EMA ternary blending sequence on mechanical properties and surface glossiness". Journal of Polymer Engineering 36, n.º 6 (1 de agosto de 2016): 625–33. http://dx.doi.org/10.1515/polyeng-2015-0299.

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Abstract Acrylonitrile-butadienestyrene (ABS)/poly(methylmethacrylate) (PMMA)/ethylene methacrylate (EMA) composites were prepared with different blending sequences. All ABS/PMMA/EMA copolymers were designed to achieve the same total chemical composition, in which ABS/PMMA was equal to 80/20 and EMA was fixed at 6 wt%. The effects of different blending sequences on the mechanical and optical properties of ABS/PMMA/EMA blends were investigated. Results indicated that the tensile strengths of ABS/PMMA/EMA blends with different blending sequences were slightly affected, whereas the Izod impact strength of blends significantly varied. The impact toughness of the blends, in which PMMA/EMA was initially blended and then combined with ABS, was approximately twice that of the other blends. This blending sequence also had surface glossiness that was superior to those of the other blends. Differential scanning calorimetry and scanning electron microscopy further revealed that blending sequence influenced the phase miscibility and dispersion of the blends, which led to different mechanical and optical properties.

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48

Jehnichen, Dieter, Doris Pospiech, Andreas Berndt, Selina C. Gomoll, Eva Natkowski y Matthias Plötner. "X-ray characterization of crosslinked methacrylate copolymers for application as dielectric layers in organic electronics". Powder Diffraction 34, S1 (25 de julio de 2019): S71—S81. http://dx.doi.org/10.1017/s0885715619000502.

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Poly(methyl methacrylate) (PMMA) is one of the most important polymers for application as a dielectric layer in organic electronics, e.g. in organic field-effect transistors. The key to improve the transistor performance is the optimization of the interface between the semiconductor and the dielectric layer. Here, the surface order in thin films of PMMA copolymers with self-organized, semifluorinated (sf) building blocks, and crosslinkable units in single layers and double layers with poly(3-hexylthiophene-2,5-diyl) (P3HT) is investigated. The chemistry of the sf copolymers is systematically varied and the influence on the self-organization in bulk and thin films is examined by a combination of scattering methods. The length of the semifluorinated side chains mainly determines the degree and type of order both in bulk as well as in thin films.

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49

Hortigüela, Verónica, Enara Larrañaga, Anna Lagunas, Gerardo A. Acosta, Fernando Albericio, Jordi Andilla, Pablo Loza-Alvarez y Elena Martínez. "Large-Area Biomolecule Nanopatterns on Diblock Copolymer Surfaces for Cell Adhesion Studies". Nanomaterials 9, n.º 4 (9 de abril de 2019): 579. http://dx.doi.org/10.3390/nano9040579.

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Cell membrane receptors bind to extracellular ligands, triggering intracellular signal transduction pathways that result in specific cell function. Some receptors require to be associated forming clusters for effective signaling. Increasing evidences suggest that receptor clustering is subjected to spatially controlled ligand distribution at the nanoscale. Herein we present a method to produce in an easy, straightforward process, nanopatterns of biomolecular ligands to study ligand–receptor processes involving multivalent interactions. We based our platform in self-assembled diblock copolymers composed of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) that form PMMA nanodomains in a closed-packed hexagonal arrangement. Upon PMMA selective functionalization, biomolecular nanopatterns over large areas are produced. Nanopattern size and spacing can be controlled by the composition of the block-copolymer selected. Nanopatterns of cell adhesive peptides of different size and spacing were produced, and their impact in integrin receptor clustering and the formation of cell focal adhesions was studied. Cells on ligand nanopatterns showed an increased number of focal contacts, which were, in turn, more matured than those found in cells cultured on randomly presenting ligands. These findings suggest that our methodology is a suitable, versatile tool to study and control receptor clustering signaling and downstream cell behavior through a surface-based ligand patterning technique.

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50

Verma, A., A. Nielsen, J. E. Mcgrath y J. S. Riffle. "Synthesis of a Model Triblock for Novel Thermoplastic Elastomers". Rubber Chemistry and Technology 64, n.º 4 (1 de septiembre de 1991): 601–9. http://dx.doi.org/10.5254/1.3538575.

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Abstract Thus far, we have been successful in preparing novel diblock and triblock copolymers comprised of poly(methyl methacrylate) and poly(butyl vinyl ether). Future work will focus on studying the morphology of both the diblock and triblock copolymers. Moreover, we are also interested in synthesizing triblocks with long poly(butyl vinyl ether) segments and short PMMA segments, since these polymers have the potential for exhibiting good elastomeric properties.

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