Journal articles: 'PHBV'

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Feijoo, Patricia, Kerly Samaniego-Aguilar, Estefanía Sánchez-Safont, Sergio Torres-Giner, Jose M. Lagaron, Jose Gamez-Perez, and Luis Cabedo. "Development and Characterization of Fully Renewable and Biodegradable Polyhydroxyalkanoate Blends with Improved Thermoformability." Polymers 14, no. 13 (June 21, 2022): 2527. http://dx.doi.org/10.3390/polym14132527.

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Poly(3-hydroxybutyrate-co-3-valerate) (PHBV), being one of the most studied and commercially available polyhydroxyalkanoates (PHAs), presents an intrinsic brittleness and narrow processing window that currently hinders its use in several plastic applications. The aim of this study was to develop a biodegradable PHA-based blend by combining PHBV with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), another copolyester of the PHA family that shows a more ductile behavior. Blends of PHBV with 20% wt., 30% wt., and 40% wt. of PHBH were obtained by melt mixing, processed by cast extrusion in the form of films, and characterized in terms of their morphology, crystallization behavior, thermal stability, mechanical properties, and thermoformability. Full miscibility of both biopolymers was observed in the amorphous phase due to the presence of a single delta peak, ranging from 4.5 °C to 13.7 °C. Moreover, the incorporation of PHBH hindered the crystallization process of PHBV by decreasing the spherulite growth rate from 1.0 µm/min to 0.3 µm/min. However, for the entire composition range studied, the high brittleness of the resulting materials remained since the presence of PHBH did not prevent the PHBV crystalline phase from governing the mechanical behavior of the blend. Interestingly, the addition of PHBH greatly improved the thermoformability by widening the processing window of PHBV by 7 s, as a result of the increase in the melt strength of the blends even for the lowest PHBH content.

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Pustan, Marius, Corina Bîrleanu, Adorján Cristea, and Horia Leonard Banciu. "Nanotribological Investigation of the Poly(3-hydroxybutyrate) Films Manufactured from the Storage Polyesters Produced by Halomonas elongata DSM 2581T." Engineering Proceedings 4, no. 1 (April 14, 2021): 29. http://dx.doi.org/10.3390/micromachines2021-09564.

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Poly(3-hydroxybutyrate) (PHB) is a natural and biodegradable storage polyester, produced by numerous bacteria, which is considered a potential substituent for conventional plastics in the packaging industry. The improvement of the PHB material lifetime often involves mechanical and tribological characterization, which can be accurately performed on thin films. In this study, we aimed at the evaluation of the tribological properties, such as adhesion force, friction coefficient and wear resistance, of different polyester films, fabricated via the solvent casting method. Three polyester films were designed in this study, each containing 1% w/v constituents as follows: a PHBh film prepared out of the PHB, extracted from the extremely halotolerant bacteria, Halomonas elongata DSM2581T, a PHBc film fabricated using a commercially available PHB, and a PHBVc film generated using the commercial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The spectroscopy-in-point of AFM was used for adhesion force measurement based on multiple tests performed in a matrix, and the AFM lateral operating mode was applied for friction analysis under a controlled normal load. The fabricated PHBh film presented a thickness between 5 and 7 µm, a lower adhesion force (14 nN) as well as a smaller friction coefficient (0.15) compared to the PHBc and PHBVc. The tribological investigations of PHBh film revealed a biodegradable material with low roughness, as well as small adhesion and friction forces. Further optimization can be performed for the improvement of the PHBh film by copolymerization with other polymers, polyesters, and reinforcers, thus generating a feasible material with advanced tribo-mechanical features.

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Deng, Wei, Yingjie Di, Jingxuan Cai, Yueyang Chen, and Shuzhong Yuan. "Target-Site Resistance Mechanisms to Tribenuron-methyl and Cross-resistance Patterns to ALS-inhibiting Herbicides of Catchweed Bedstraw (Galium aparine) with Different ALS Mutations." Weed Science 67, no. 2 (December 18, 2018): 183–88. http://dx.doi.org/10.1017/wsc.2018.70.

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AbstractCatchweed bedstraw (Galium aparine L.) is a problematic dicot weed that occurs in major winter wheat (Triticum aestivum L.) fields in China. Tribenuron-methyl has been widely used to control broadleaf weeds since 1988 in China. However, overuse has led to the resistance evolution of G. aparine to tribenuron-methyl. In this study, 20 G. aparine populations collected from Shandong and Henan provinces were used to determine tribenuron-methyl resistance and target-site resistance mechanisms. In dose–response experiments, 12 G. aparine populations showed different resistance levels (2.92 to 842.41-fold) to tribenuron-methyl compared with the susceptible population. Five different acetolactate synthase (ALS) mutations (Pro-197-Leu, Pro-197-Ser, Pro-197-His, Asp-376-Glu, and Trp-574-Leu) were detected in different resistant populations. Individuals heterozygous for Pro-197-Ser and Trp-574-Leu mutations were also observed in a resistant population (HN6). In addition, pHB4 (Pro-197-Ser), pHB7 (Pro-197-His), pHB8 (Pro-197-Leu), pHB5 (Asp-376-Glu), and pHB3 (Trp-574-Leu) subpopulations individually homozygous for specific ALS mutations were generated to evaluate the cross-resistance to ALS-inhibiting herbicides. The pHB4, pHB7, pHB8, pHB5, and pHB3 subpopulations all were resistant to sulfonylurea, pyrazosulfuron-ethyl, triazolopyrimidine, flumetsulam, sulfonylamino-carbonyl-triazolinone, flucarbazone-sodium, pyrimidinyl thiobenzoate, pyribenzoxim, and the imidazolinone imazethapyr. These results indicated the diversity of the resistance-conferring ALS mutations in G. aparine, and all these mutations resulted in broad cross-resistance to five kinds of ALS-inhibiting herbicides.

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Kim, Sinil, Byeongsuk Ha, Minseek Kim, and Hyeon-Su Ro. "Investigation of Mating Pheromone–Pheromone Receptor Specificity in Lentinula edodes." Genes 11, no. 5 (May 4, 2020): 506. http://dx.doi.org/10.3390/genes11050506.

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The B mating-type locus of Lentinula edodes, a representative edible mushroom, is highly complex because of allelic variations in the mating pheromone receptors (RCBs) and the mating pheromones (PHBs) in both the Bα and Bβ subloci. The complexity of the B mating-type locus, five Bα subloci with five alleles of RCB1 and nine PHBs and three Bβ subloci with 3 alleles of RCB2 and five PHBs, has led us to investigate the specificity of the PHB–RCB interaction because the interaction plays a key role in non-self-recognition. In this study, the specificities of PHBs to RCB1-2 and RCB1-4 from the Bα sublocus and RCB2-1 from the Bb sublocus were investigated using recombinant yeast strains generated by replacing STE2, an endogenous yeast mating pheromone receptor, with the L. edodes RCBs. Fourteen synthetic PHBs with C-terminal carboxymethylation but without farnesylation were added to the recombinant yeast cells and the PHB–RCB interaction was monitored by the expression of the FUS1 gene—a downstream gene of the yeast mating signal pathway. RCB1-2 (Bα2) was activated by PHB1 (4.3-fold) and PHB2 (2.1-fold) from the Bα1 sublocus and RCB1-4 (Bα4) was activated by PHB5 (3.0-fold) and PHB6 (2.7-fold) from the Bα2 sublocus and PHB13 (3.0-fold) from the Bα5 sublocus. In particular, PHB3 from Bβ2 and PHB9 from Bβ3 showed strong activation of RCB2-1 of the Bβ1 sublocus by 59-fold. The RCB–PHB interactions were confirmed in the monokaryotic S1–10 strain of L. edodes by showing increased expression of clp1, a downstream gene of the mating signal pathway and the occurrence of clamp connections after the treatment of PHBs. These results indicate that a single PHB can interact with a non-self RCB in a sublocus-specific manner for the activation of the mating pheromone signal pathways in L. edodes.

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Abbasi, Maryam, Dikshya Pokhrel, Erik R. Coats, Nicholas M. Guho, and Armando G. McDonald. "Effect of 3-Hydroxyvalerate Content on Thermal, Mechanical, and Rheological Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biopolymers Produced from Fermented Dairy Manure." Polymers 14, no. 19 (October 3, 2022): 4140. http://dx.doi.org/10.3390/polym14194140.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with various 3-hydroxyvalerate (3HV) contents biosynthesized by mixed microbial consortia (MMC) fed fermented dairy manure at the large-scale level was assessed over a 3-month period. The thermal, mechanical, and rheological behavior and the chemical structure of the extracted PHBV biopolymers were studied. The recovery of crude PHBV extracted in a large Soxhlet extractor with CHCl3 for 24 h ranged between 20.6% to 31.8% and purified to yield between 8.9% to 26.9% all based on original biomass. 13C-NMR spectroscopy revealed that the extracted PHBVs have a random distribution of 3HV and 3-hydroxybutyrate (3HB) units and with 3HV content between 16% and 24%. The glass transition temperature (Tg) of the extracted PHBVs varied between −0.7 and −7.4 °C. Some of the extracted PHBVs showed two melting temperatures (Tm) which the lower Tm1 ranged between 126.1 °C and 159.7 °C and the higher Tm2 varied between 152.1 °C and 170.1 °C. The weight average molar mass of extracted PHBVs was wide ranging from 6.49 × 105 g·mol−1 to 28.0 × 105 g·mol−1. The flexural and tensile properties were also determined. The extracted polymers showed a reverse relationship between the 3HV content and Young’s modulus, tensile strength, flexural modulus, and flexural strength properties.

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Yun, So Hee, Ga Young Jun, Kwan Han Yoon, Yong Soon Park, Young Jin Kim, Inn Kyu Kang, and Oh Hyeong Kwon. "Co-Electrospinning of Microbial Polyester/Gelatin and their Interaction with Fibroblasts." Key Engineering Materials 342-343 (July 2007): 201–4. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.201.

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Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibrous matrix containing gelatin was fabricated by electrospinning method. The average diameter of electrospun PHBV/Gelatin (1:1) nanofibers was 600 nm determined by FE-SEM. ATR-FTIR and ESCA measurements were used to confirm the presence of gelatin in PHBV/Gelatin nanofibers. Human fibroblasts' behavior on PHBV/Gelatin nanofibrous matrix has been investigated. Fibroblasts were well attached on the surface of control PHBV and PHBV/Gelatin nanofibers. Initial cell attachment on PHBV/Gelatin nanofibers was higher than that of control PHBV nanofibers. Gelatin has many RGD moiety that mediate cell attachment. From this reason, initial cell attachment increased on the surface of PHBV/Gelatin nanofibers. From the results, coelectrospinning of PHBV and gelatin is a promising method for tissue engineering scaffold.

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Guo, Yong, Li Wang, Yuxia Chen, Panpan Luo, and Tong Chen. "Properties of Luffa Fiber Reinforced PHBV Biodegradable Composites." Polymers 11, no. 11 (October 27, 2019): 1765. http://dx.doi.org/10.3390/polym11111765.

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In this study, composites of poly (hydroxybutyrate-co-valerate) (PHBV) with untreated luffa fibers (ULF) and NaOH-H2O2 treated luffa fibers (TLF) were prepared by hot press forming. The properties of luffa fibers (LFs) and composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and other analysis methods. Results showed that pre-treatment effectively removed pectin, hemicellulose, and lignin, thus reducing the moisture absorptivity of LFs. The flexural strength of TLF/PHBV was higher than that of ULF/PHBV. With 60% LF content, the flexural strengths of ULF/PHBV and TLF/PHBV reached 75.23 MPa and 90.73 MPa, respectively, 219.7% and 285.6% more than that of pure PHBV. Water absorptivities of composites increased with increase in LF content. Water absorptivity of TLF/PHBV was lower than that of ULF/PHBV. The flexural strengths of composites decreased after immersion in water at room temperature. Meanwhile, flexural strength of TLF/PHBV was lower than that of ULF/PHBV. Pretreatment of LFs effectively improved the bonding between fibers and PHBV, resulting in enhanced and thus improved the moisture resistance of composites.

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Krikštanavičienė, Kira, Sigitas Stanys, and Vaida Jonaitienė. "Comparative Investigation of Mechanical–Physical Characteristics of Biodegradable and Non-Degradable Yarns." Autex Research Journal 14, no. 2 (June 1, 2014): 61–72. http://dx.doi.org/10.2478/aut-2014-0001.

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Abstract This article presents the results from investigations of tensile tests, absorbency test and degradation test of biodegradable and non- or partly biodegradable yarns produced from pure poly hydroxybutyrate-co-valerate (PHBV), poly (lactide acid) (PLA), isotactic polypropylene (iPP) polymers and their blends. The results indicate that mechanical-physical properties of PHBV are improved by adding PLA and iPP to PHBV. The main results indicate that the PHBV/PLA and PHBV/iPP (70/30) blends had better mechanical properties than pure PHBV, as well as improved immiscibility and the same or lower degradation in sodium chloride solution, respectively. The PHBV/PLA and PHBV/iPP blends showed a tendency for lower crystallinity and stiffness of the yarns, rendering them less stiff and fragile. The absorption tests showed that absorption dynamic process depends on the structure and raw materials of the yarns. The disinfectant in all samples is absorbed faster than blood. Research results showed that pure PHBV yarns have good hydrophobic properties, compared with pure PLA and iPP yarns. The use of additional PLA and iPP polymers changed the wetting behaviour of yarns. Absorption time of blended yarns in disinfectant liquid decreases and absorption time in the case of blood significantly increases in comparison with PLA and iPP yarns and decreases compared with PHBV yarns. The degradation tests (within 90 days in a solution of sodium chloride) showed that pure PHBV and PHBV/PLA blends degraded at different rates but with the loss of the same weight, while pure PHBV and PHBV/iPP blends degraded at the same rate, but PHBV/iPP blends had worse destruction results. Such improvements are expected to be important for the practical application of PHBV in some fields

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Zhou, Zhe, Hou Yong Yu, Mei Fang Zhu, and Zong Yi Qin. "Effects of Microcrystalline Cellulose on the Thermal Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)." Advanced Materials Research 284-286 (July 2011): 1778–81. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.1778.

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The composites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with different microcrystalline cellulose (MCC) contents were prepared by a solvent casting method. The effects of MCC on the thermal properties of PHBV were studied by TGA and DSC. The DSC results showed that the melt crystallization temperature of the PHBV/MCC increased from 41.9 °C for PHBV to 59.8 °C for the composites containing 20 wt. % MCC, which indicated that the crystallization of PHBV became easier with the addition of MCC. It also illustrated that the MCC could be used as an effective nucleation agent for the crystallization of PHBV. Moreover, it was found that the thermal stability of the PHBV/MCC composites increased compared with the neat PHBV.

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Wang, Lu, Chang Kun Ding, Hao Bo Shi, Bo Wen Cheng, and Wu Qiong. "Preparation and Properties of Bacterial Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) Fibers." Advanced Materials Research 335-336 (September 2011): 1477–80. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.1477.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is biosynthetic aliphatic polyester with good biocompatibility and biodegradability. In this paper, PHBV biodegradable fibers were manufactured by melt-spinning, and the drawing procedure and heat setting of the fibers were applied. By X-ray diffraction, SEM and stress-strain measurements, the crystalline and mechanical properties of PHBV fibers were investigated. The results showed that β-form crystals were obtained in some PHBV fibers. Surface fibrillation phenomenon occurred in the oriented PHBV fibers. The tensile strength of PHBV fibers increased with increasing the draw ratio. The tensile strength of 10 times stretched PHBV fibers can reach 227 MPa.

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Kuntanoo, Karndarthip, Sarunya Promkotra, and Pakawadee Kaewkannetra. "Fabrication of Novel Polyhydroxybutyrate-co-Hydroxyvalerate (PHBV) Mixed with Natural Rubber Latex." Key Engineering Materials 659 (August 2015): 404–8. http://dx.doi.org/10.4028/www.scientific.net/kem.659.404.

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Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is mixed with natural rubber latex to make better mechanical properties of PHBV. The various ratios between PHBV and natural rubber latex are examined to improve their mechanical properties. The PHBV are solid, easily broken, while natural rubber is excessive elastic materials. Concentrations of the employed PHBV solution are 1, 2, and 3 (%w/v). The mixtures of this solution to natural rubber latex are fabricated the biofilms in three different ratios, 4:6, 5:5, and 6:4, respectively. The films are characterized by electron microscope, universal testing machine, and differential scanning calorimetry (DSC). The electron micrographs of the mixed films and unmixed PHBV yield the lowest void distributions in 3%w/v PHBV. For mechanical properties, the averaged elastic moduli of 1, 2, and 3 (%w/v PHBV) mixed films are 773, 955 and 1,008 kPa, respectively. Their tensile strengths increase with increasing the PHBV concentrations. A similar trend is also found in elastic modulus. The crystallization and melting behavior of pure PHBV and the mixed films are examined by DSC. Melting transition temperatures of pure PHBV exhibit two melting peaks at 154°C and 173°C. In addition, the melting peaks of the mixed films remain in the range of 152-156°C and 168-171°C, respectively. According to their morphology, void distributions reduce twice, compared to the unmixed PHBV. Mechanical properties and thermal analysis indicate that the mixed PHBV can be improved their properties with more resilient and wide range temperature than usual.

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Ribas, Montanheiro, Montagna, Prado, Campos, and Thim. "Water Uptake in PHBV/Wollastonite Scaffolds: A Kinetics Study." Journal of Composites Science 3, no. 3 (July 16, 2019): 74. http://dx.doi.org/10.3390/jcs3030074.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a widely studied polymer and it has been found that porous PHBV materials are suitable for substrates for cell cultures. A crucial factor for scaffolds designed for tissue engineering is the water uptake. This property influences the transport of water and nutrients into the scaffold, which promotes cell growth. PHBV has significant hydrophobicity, which can harm the production of cells. Thus, the addition of α-wollastonite (WOL) can modify the PHBV scaffold’s water uptake. To our knowledge, a kinetics study of water uptake of α-wollastonite phase powder and the PHBV matrix has not been reported. In this work, PHBV and WOL, (PHBV/WOL) films were produced with 0, 5, 10, and 20 wt % of WOL. Films were characterized, and the best concentrations were chosen to produce PHBV/WOL scaffolds. The addition of WOL in concentrations up to 10 wt % increased the cell viability of the films. MTT analysis showed that PHBV/5%WOL and PHBV/10%WOL obtained cell viability of 80% and 98%, respectively. Therefore, scaffolds with 0, 5 and 10 wt % of WOL were fabricated by thermally induced phase separation (TIPS). Scaffolds were characterized with respect to morphology and water uptake in assay for 65 days. The scaffold with 10 wt % of WOL absorbed 44.1% more water than neat PHBV scaffold, and also presented a different kinetic mechanism when compared to other samples. Accordingly, PHBV/WOL scaffolds were shown to be potential candidates for biological applications.

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Zhao, Xiaoying, Katrina Cornish, and Yael Vodovotz. "Synergistic Mechanisms Underlie the Peroxide and Coagent Improvement of Natural-Rubber-Toughened Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Mechanical Performance." Polymers 11, no. 3 (March 26, 2019): 565. http://dx.doi.org/10.3390/polym11030565.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising bio-based and biodegradable thermoplastic with restricted industrial applications due to its brittleness and poor processability. Natural rubber (NR) has been used as a toughening agent, but further physical improvements are desired. In this study, rubber toughening efficiency was significantly improved through the synergistic use of a trifunctional acrylic coagent and an organic peroxide during reactive extrusion of PHBV and NR. The rheological, crystallization, thermal, morphological, and mechanical properties of PHBV/NR blends with 15% rubber loading were characterized. The peroxide and coagent synergistically crosslinked the rubber phase and grafted PHBV onto rubber backbones, leading to enhanced rubber modulus and cohesive strength as well as improved PHBV–rubber compatibility and blend homogeneity. Simultaneously, the peroxide–coagent treatment decreased PHBV crystallinity and crystal size and depressed peroxy-radical-caused PHBV degradation. The new PHBV/NR blends had a broader processing window, 75% better toughness (based on the notched impact strength data), and 100% better ductility (based on the tensile elongation data) than pristine PHBV. This new rubber-toughened PHBV material has balanced mechanical performance comparable to that of conventional thermoplastics and is suitable for a wide range of plastic applications.

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Sultana, Naznin, and Tareef Hayat Khan. "In VitroDegradation of PHBV Scaffolds and nHA/PHBV Composite Scaffolds Containing Hydroxyapatite Nanoparticles for Bone Tissue Engineering." Journal of Nanomaterials 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/190950.

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This paper investigated the long-termin vitrodegradation properties of scaffolds based on biodegradable polymers and osteoconductive bioceramic/polymer composite materials for the application of bone tissue engineering. The three-dimensional porous scaffolds were fabricated using emulsion-freezing/freeze-drying technique using poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) which is a natural biodegradable and biocompatible polymer. Nanosized hydroxyapatite (nHA) particles were successfully incorporated into the PHBV scaffolds to render the scaffolds osteoconductive. The PHBV and nHA/PHBV scaffolds were systematically evaluated using various techniques in terms of mechanical strength, porosity, porous morphology, andin vitrodegradation. PHBV and nHA/PHBV scaffolds degraded over time in phosphate-buffered saline at 37°C. PHBV polymer scaffolds exhibited slow molecular weight loss and weight loss in thein vitrophysiological environment. Accelerated weight loss was observed in nHA incorporated PHBV composite scaffolds. An increasing trend of crystallinity was observed during the initial period of degradation time. The compressive properties decreased more than 40% after 5-monthin vitrodegradation. Together with interconnected pores, high porosity, suitable mechanical properties, and slow degradation profile obtained from long-term degradation studies, the PHBV scaffolds and osteoconductive nHA/PHBV composite scaffolds showed promises for bone tissue engineering application.

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ZHOU, MINGSHU, and DONG YU. "Cartilage tissue engineering using PHBV and PHBV/Bioglass scaffolds." Molecular Medicine Reports 10, no. 1 (April 15, 2014): 508–14. http://dx.doi.org/10.3892/mmr.2014.2145.

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Langford, Alexandra, Clement Matthew Chan, Steven Pratt, Christopher J. Garvey, and Bronwyn Laycock. "The morphology of crystallisation of PHBV/PHBV copolymer blends." European Polymer Journal 112 (March 2019): 104–19. http://dx.doi.org/10.1016/j.eurpolymj.2018.12.022.

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Fei, Bin, Cheng Chen, Hang Wu, Shuwen Peng, Xiuyan Wang, and Lisong Dong. "Comparative study of PHBV/TBP and PHBV/BPA blends." Polymer International 53, no. 7 (June 8, 2004): 903–10. http://dx.doi.org/10.1002/pi.1460.

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Baek, Jin-Young, Zhi-Cai Xing, Giseop Kwak, Keun-Byoung Yoon, Soo-Young Park, Lee Soon Park, and Inn-Kyu Kang. "Fabrication and Characterization of Collagen-Immobilized Porous PHBV/HA Nanocomposite Scaffolds for Bone Tissue Engineering." Journal of Nanomaterials 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/171804.

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The porous composite scaffolds (PHBV/HA) consisting of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and hydroxyapatite (HA) were fabricated using a hot-press machine and salt-leaching. Collagen (type I) was then immobilized on the surface of the porous PHBV/HA composite scaffolds to improve tissue compatibility. The structure and morphology of the collagen-immobilized composite scaffolds (PHBV/HA/Col) were investigated using a scanning electron microscope (SEM), Fourier transform infrared (FTIR), and electron spectroscopy for chemical analysis (ESCA). The potential of the porous PHBV/HA/Col composite scaffolds for use as a bone scaffold was assessed by an experiment with osteoblast cells (MC3T3-E1) in terms of cell adhesion, proliferation, and differentiation. The results showed that the PHBV/HA/Col composite scaffolds possess better cell adhesion and significantly higher proliferation and differentiation than the PHBV/HA composite scaffolds and the PHBV scaffolds. These results suggest that the PHBV/HA/Col composite scaffolds have a high potential for use in the field of bone regeneration and tissue engineering.

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Wang, Kun Yan, and Feng Cao. "Effect of CaCO₃ on Thermal and Crystalline Morphology Properties of Biodegradable PHBV." Advanced Materials Research 781-784 (September 2013): 542–45. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.542.

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Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/CaCO3 blends were prepared by solution blend method. The effect of CaCO3 on the thermal and crystalline morphology properties was studied by differential scanning calorimetry (DSC), thermogravimetry (TG) and polarizing optical microscopy (POM) analyses. DSC showed the CaCO3 affected the crystallization behavior of PHBV as heterogeneous nucleation agent. TG results indicated better processability of the blends with 3wt% CaCO3 than that of pure PHBV. Integrated Maltese crossed spherulitic morphologies were revealed for both pure PHBV and PHBV/CaCO3 blend. While small-sized PHBV spherulites were formed when CaCO3 added to PHBV.

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Sun, Xichao, and Yeqian Ge. "Preparation and Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Polypropylene Grafting Maleic Anhydride Two-Component Materials." Fibres and Textiles in Eastern Europe 26, no. 3(129) (June 7, 2018): 17–22. http://dx.doi.org/10.5604/01.3001.0011.7298.

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In order to provide a theoretical basis for the preparation and spinnability of two-component materials, poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) and polypropylene grafting maleic anhydride (PP-g-MAH) blends were prepared by melt mixing with different ratios (100/0, 75/25, 50/50, 25/75, 0/100). Properties of the blends system were investigated by means of a mixed rheometer, scanning electron microscope, simultaneous thermal analyser, differential scanning calorimetry and X-ray diffraction. The results demonstrate that PHBV/PP-g-MAH blends exhibit different morphology of the sea-island with a change in the mix ratio. The initial thermal decomposition temperature of PHBV in the blending system is over 250 °C, which means the thermal stability of PHBV is markedly improved. The crystallisation of PHBV varied according to the blending process parameter. When the cooling velocity increases, the crystallisation peak becomes wide, the temperature of crystallisation decreases, and the crystallisation temperature of PHBV increases significantly. PHBV has a high sensitivity to variation in the shear rate, and PHBV/PP-g-MAH blends have the mixing characteristic of shear thinned liquid. There is no diffraction peak at 2θ = 22.8°, and this result certifies that PP-g-MAH changes the crystal form of PHBV. and that PP-g-MAH addition is beneficial to the spinnability of PHBV. Results show that the interplay between PHBV and PP-g-MAH is of great significance and universal for both plastics and fibres.

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Mahamud, Syarifah Nuraqmar Syed, Ovinesh Ganesan, Mohd Hanif Mohd Pisal, and Nurul Ekmi Rabat. "Effect of graphene nanoplatelet addition on the electrical conductivity of poly(hydroxybutyrate-co-hydroxyvalerate) biocomposites." Journal of Physics: Conference Series 2080, no. 1 (November 1, 2021): 012010. http://dx.doi.org/10.1088/1742-6596/2080/1/012010.

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Abstract Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is one of the most promising biodegradable polymers used in many applications due to its biodegradability and non-toxicity. However, the usage of PHBV in electronic, biomedical, and biosensor applications has been limited due to its poor electrical properties. This study shows a simple method of producing and enhancing the electrical conductivity of PHBV-based biocomposites by adding graphene nanoplatelet (GNP) as a conductive filler. The biocomposite films were prepared using the solvent casting method, consist of five GNP loading (0-5 wt. %). The prepared PHBV/GNP biocomposites show enhanced electrical conductivity compared to neat PHBV. PHBV/GNP biocomposite with 5 wt. % filler loading exhibits the highest electrical conductivity at 3.83 × 10−3 S/cm. Higher crystalline regions in the PHBV/GNP biocomposites have facilitated the transfer of electrons between PHBV, resulting in the formation of conductive biocomposites, as evident from X-ray diffraction (XRD) characterization.

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Ke, Yu, Gang Wu, and Yingjun Wang. "PHBV/PAM Scaffolds with Local Oriented Structure through UV Polymerization for Tissue Engineering." BioMed Research International 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/157987.

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Locally oriented tissue engineering scaffolds can provoke cellular orientation and direct cell spread and migration, offering an exciting potential way for the regeneration of the complex tissue. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds with locally oriented hydrophilic polyacrylamide (PAM) inside the macropores of the scaffolds were achieved through UV graft polymerization. The interpenetrating PAM chains enabled good interconnectivity of PHBV/PAM scaffolds that presented a lower porosity and minor diameter of pores than PHBV scaffolds. The pores with diameter below 100 μm increased to 82.15% of PHBV/PAM scaffolds compared with 31.5% of PHBV scaffolds. PHBV/PAM scaffold showed a much higher compressive elastic modulus than PHBV scaffold due to PAM stuffing. At 5 days of culturing, sheep chondrocytes spread along the similar direction in the macropores of PHBV/PAM scaffolds. The locally oriented PAM chains might guide the attachment and spreading of chondrocytes and direct the formation of microfilamentsviacontact guidance.

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da Silva, David C., Ana Paula Lemes, Lilia M. Guerrini, and Fernando H. Cristovan. "Preparation and Characterization of Blends of Polyaniline with Poly(Hydroxybutyrate-Co-Valerate)." MRS Proceedings 1498 (2013): 115–20. http://dx.doi.org/10.1557/opl.2013.57.

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ABSTRACTIn this study the PANI/PHBV blends were prepared and thermal properties, crystallization behavior, microstructure of the blends were investigated. The PANI/PHBV blends were prepared by dissolution of PANI (emeraldine base doped with dodecylbenzenesulphonic acid, DBSA) and PHBV in chloroform and films were obtained by casting. PANI amount in the blend was varied from 0.1 to 1% wt. PANI/PHBV blends were characterized by FTIR spectroscopy and the thermal behavior were analyzed by differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). FTIR spectra of the pure PHBV and PANI/PHBV blend had similar peaks. However, blends spectra show an enlargement of bands, due interaction of the chain PANI with PHBV matrix. The crystallization behaviors were investigated using DSC, with at a scanning rate of 10oCmin−1. Curve of pure PHBV showed two melting peaks (159.1°C and 172.3°C). With the increase of PANI amount in the PHBV matrix, both of the melting peaks became wider and shifted to lower temperatures. The decrease trend of first and second melting points with increase of PANI amount, suggests a reduction in the crystallinity of the blends.

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Yu, Hou Yong, and Zong Yi Qin. "Effect of Cellulose Nanocrystal on Crystallization Behavior of Poly(3–hydroxybutyrate–co–3–hydroxyvalerate)." Advanced Materials Research 430-432 (January 2012): 20–23. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.20.

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The biodegradable nanocomposites of poly (3–hydroxybutyrate–co–3–hydroxyvalerate) (PHBV) with different cellulose nanocrystals (CNCs) contents were prepared by a solvent casting method. The effects of CNCs on the crystallization behavior of PHBV were studied by DSC. The DSC results showed that compared to PHBV, the melt crystallization temperature increased to 92.3 °C for the nanocomposites with 10 wt. % CNCs, which indicated that the crystallization of PHBV became easier with the addition of CNCs. Moreover, the non–isothermal crystallization kinetics study illustrated that overall crystallization rate of PHBV in the nanocomposites was faster than that of neat PHBV, which should be attributed to the strong heterogeneous nucleation of CNCs.

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Kovalcik, Adriana, Stanislav Obruca, Michal Kalina, Michal Machovsky, Vojtech Enev, Michaela Jakesova, Marketa Sobkova, and Ivana Marova. "Enzymatic Hydrolysis of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Scaffolds." Materials 13, no. 13 (July 5, 2020): 2992. http://dx.doi.org/10.3390/ma13132992.

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Polyhydroxyalkanoates (PHAs) are hydrolyzable bio-polyesters. The possibility of utilizing lignocellulosic waste by-products and grape pomace as carbon sources for PHA biosynthesis was investigated. PHAs were biosynthesized by employing Cupriavidus necator grown on fructose (PHBV-1) or grape sugar extract (PHBV-2). Fifty grams of lyophilized grape sugar extract contained 19.2 g of glucose, 19.1 g of fructose, 2.7 g of pectin, 0.52 g of polyphenols, 0.51 g of flavonoids and 7.97 g of non-identified rest compounds. The grape sugar extract supported the higher production of biomass and modified the composition of PHBV-2. The biosynthesized PHAs served as matrices for the preparation of the scaffolds. The PHBV-2 scaffolds had about 44.2% lower crystallinity compared to the PHBV-1 scaffolds. The degree of crystallinity markedly influenced the mechanical behavior and enzymatic hydrolysis of the PHA scaffolds in the synthetic gastric juice and phosphate buffer saline solution with the lipase for 81 days. The higher proportion of amorphous moieties in PHBV-2 accelerated enzymatic hydrolysis. After 81-days of lasting enzymatic hydrolysis, the morphological changes of the PHBV-1 scaffolds were negligible compared to the visible destruction of the PHBV-2 scaffolds. These results indicated that the presence of pectin and phenolic moieties in PHBV may markedly change the semi-crystalline character of PHBV, as well as its mechanical properties and the course of abiotic or enzymatic hydrolysis.

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Liu, Pei, Long Chen, Jun Xu, Mei Fang Zhu, and Zong Yi Qin. "Mechanical Properties of Poly(3-hydrobutyrate-co-hydroxyvalerate)/ Biodegradable Hyperbranched Poly(ester amide) Blends." Materials Science Forum 745-746 (February 2013): 436–41. http://dx.doi.org/10.4028/www.scientific.net/msf.745-746.436.

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Biodegradable composites were prepared by adding hyperbranched poly (ester amide) (HBPs) into poly (3-hydroxybutyrate-co-3-hydrovalerate) (PHBV) through melt blending method. It was found that the tensile strength and toughness of PHBV were simultaneously enhanced by the addition of HBPs. Compared with neat PHBV, the tensile strength of the composite increased about 23% from 20.96 to 25.87 MPa for the content of 2.5 wt.% HBPs, and more remarkable enhancement in tensile elongation at break can be achieved by about 88% for 5 wt.% HBPs. The influences of HBPs on crystallization, thermal and fracture morphologies of PHBV were further evaluated by using differential scanning calorimeter and scanning electron microscope, respectively. The decrease in the crystallinity of PHBV and high dispersion of the HBPs in PHBV matrix were observed, which should contribute to the improvement on the mechanical properties of PHBV.

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Liang, Guo Lei, Zhi Hong Li, Ji Min Wu, Xiang Zhao, Wei Juan Jiang, Zi Hao Chen, Jing Guan, Shu Jie Huang, and Xi Zheng Zhang. "Preparation and Properties of Poly(lactic Acid) Fiber Reinforced PHBV Composite." Applied Mechanics and Materials 420 (September 2013): 107–13. http://dx.doi.org/10.4028/www.scientific.net/amm.420.107.

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Purposes: This study is to improve the mechanical properties and machinability performance of PHBV. Procedures: PLA/PHBV composites were prepared by dry blend in the melt mixing. The contents of PLA fiber in PHBV matrix are 0, 1, 3, 5, 8 and 10 wt. %. Methods: PLA/PHBV composites were subjected to mechanical property, thermal and morphology evaluation. Results: The results showed the immiscibility of PLA fiber and PHBV matrix. The excellent mechanical properties of the composite (the content of PLA fiber is 8 wt. %) were higher than those of neat PHBV. The micrograph of the fracture surfaces showed that the addition of PLA fiber evidently improved the toughness of PLA/PHBV blends and showed a broad spectrum of PLA fiber diameter (about 200 nm). Conclusions: The improvements were due to the efficient of the PLA fiber as the reinforcement. And the blends showed a significant ductile plastic deformation. The PLA/PHBV blends can be used for a wide range of multifunctional biomedical materials such as the internal fixation of fracture.

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Wang, Li, Yong Guo, Yuxia Chen, Tong Chen, Shiliu Zhu, Tingting Zhang, and Shengquan Liu. "Enhanced Mechanical and Water Absorption Properties of Rice Husk-Derived Nano-SiO2 Reinforced PHBV Composites." Polymers 10, no. 9 (September 13, 2018): 1022. http://dx.doi.org/10.3390/polym10091022.

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Poly(3-hydroxybutyrate–co–3-hydroxyvalerate) (PHBV) is a biodegradable polymer and has several potential applications. Herein, we have used a rich biomass resource, rice husk, to obtain rice husk nano-SiO2 (RHNS) and prepared RHNS/PHBV composites by using hot-press molding. The results showed that the amorphous nature of spherical nano-SiO2 particles with an average diameter of 40–80 nm was obtained. The tensile strength and flexural strength of the RHNS/PHBV-3 composite reached up to 23.515 and 75.669 MPa, respectively, corresponding to an increase of 33.65% and 15.54% as compared to pure PHBV. The enhanced mechanical properties of the RHNS/PHBV composite can be attributed to the uniform dispersion and strong interfacial bonding of RHNS with the PHBV matrix. In addition, the water absorption rate of the RHNS/PHBV composite increased from 0.26% to 0.35% and the water swelling ratio followed the given order in different directions: thickness > width > length. Furthermore, the initial degradation temperature and residual rate of combustion at 700 °C of the composites increased with higher content of RHNS, which represents the enhanced thermal stability of RHNS/PHBV composites. In summary, RHNS served as an excellent reinforcement and RHNS/PHBV composites have shown promising properties for various potential applications.

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Jin, Anyi, Luis J. del Valle, and Jordi Puiggalí. "Copolymers and Blends Based on 3-Hydroxybutyrate and 3-Hydroxyvalerate Units." International Journal of Molecular Sciences 24, no. 24 (December 8, 2023): 17250. http://dx.doi.org/10.3390/ijms242417250.

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This review presents a comprehensive update of the biopolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), emphasizing its production, properties, and applications. The overall biosynthesis pathway of PHBV is explored in detail, highlighting recent advances in production techniques. The inherent physicochemical properties of PHBV, along with its degradation behavior, are discussed in detail. This review also explores various blends and composites of PHBV, demonstrating their potential for a range of applications. Finally, the versatility of PHBV-based materials in multiple sectors is examined, emphasizing their increasing importance in the field of biodegradable polymers.

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Rodríguez-Cendal, Ana Isabel, Iván Gómez-Seoane, Francisco Javier de Toro-Santos, Isaac Manuel Fuentes-Boquete, José Señarís-Rodríguez, and Silvia María Díaz-Prado. "Biomedical Applications of the Biopolymer Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV): Drug Encapsulation and Scaffold Fabrication." International Journal of Molecular Sciences 24, no. 14 (July 19, 2023): 11674. http://dx.doi.org/10.3390/ijms241411674.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable and biocompatible biopolymer that has gained popularity in the field of biomedicine. This review provides an overview of recent advances and potential applications of PHBV, with special emphasis on drug encapsulation and scaffold construction. PHBV has shown to be a versatile platform for drug delivery, offering controlled release, enhanced therapeutic efficacy, and reduced side effects. The encapsulation of various drugs, such as anticancer agents, antibiotics, and anti-inflammatory drugs, in PHBV nanoparticles or microspheres has been extensively investigated, demonstrating enhanced drug stability, prolonged release kinetics, and increased bioavailability. Additionally, PHBV has been used as a scaffold material for tissue engineering applications, such as bone, cartilage, and skin regeneration. The incorporation of PHBV into scaffolds has been shown to improve mechanical properties, biocompatibility, and cellular interactions, making them suitable for tissue engineering constructs. This review highlights the potential of PHBV in drug encapsulation and scaffold fabrication, showing its promising role in advancing biomedical applications.

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Montanheiro, Thaís Larissa do Amaral, Vanessa Modelski Schatkoski, Denisse Esther Mallaupoma Camarena, Thais Cardoso de Oliveira, Diego Morais da Silva, Mariana Raquel da Cruz Vegian, Luiz Henrique Catalani, Cristiane Yumi Koga-Ito, and Gilmar Patrocínio Thim. "Evaluating the Cytotoxicity of Functionalized MWCNT and Microbial Biofilm Formation on PHBV Composites." C 10, no. 2 (March 31, 2024): 33. http://dx.doi.org/10.3390/c10020033.

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This study focuses on the cytotoxic evaluation of functionalized multi-walled carbon nanotubes (MWCNT) and microbial biofilm formation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanocomposites incorporating MWCNTs functionalized with gamma-aminobutyric acid (GABA) and carboxyl groups. The materials were characterized for cytotoxicity to fibroblasts and antimicrobial effects against Escherichia coli, Staphylococcus aureus and Candida albicans. The functionalization of MWCNTs was performed through oxidation (CNT-Ox) and GABA attachment (CNT-GB). The PHBV/CNT nanocomposites were produced via melt mixing. All MWCNT suspensions showed non-toxic behaviors after 24 h of incubation (viability higher than 70%); however, prolonged incubation and higher concentrations led to increased cytotoxicity. The antibacterial potential of PHBV/CNT nanocomposites against S. aureus showed a reduction in biofilm formation of 64% for PHBV/CNT-GB and 20% for PHBV/CNT-Ox, compared to neat PHBV. Against C. albicans, no reduction was observed. The results indicate promising applications for PHBV/CNT nanocomposites in managing bacterial infections, with GABA-functionalized CNTs showing enhanced performance.

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Ko, Young Gwang, Hyeon Ae Jeon, Kwan Han Yoon, Young Chul Kim, Chang Hyun Ahn, Young Jin Kim, and Oh Hyeong Kwon. "Development of Rapid Cell Recovery System Using Temperature-Responsive Nanofiber Surfaces." Key Engineering Materials 342-343 (July 2007): 249–52. http://dx.doi.org/10.4028/www.scientific.net/kem.342-343.249.

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PHBV ultrafine fibers were fabricated by electrospinning process. Electrospun PHBV fiber structures revealed randomly aligned fibers with average diameter of 400 nm. PIPAAm was grafted on the surface of PHBV nanofibrous mat by electron beam irradiation. PIPAAm-grafted PHBV mats were determined by ATR-FTIR and ESCA. Water contact angles were determined by a sessile drop method at 20 and 37. To examine the tissue compatibility, human fibroblasts were evenly seeded onto PIPAAm-grafted PHBV mat and cast film, ungrafted PHBV mat and film. Attached and spread fibroblasts on nanofibrous mat were proliferated more rapidly than that of flat film surface. Initial cell attachment on PIPAAm-grafted surfaces was higher than ungrafted surfaces. The surface property changed to hydrophilic by PIPAAm graft, which increased initial cell attachment. Detachment of single cells from PIPAAm-grafted PHBV matrixes was measured by low temperature treatment after incubation at 37. Cultured cells were rapidly detached from PIPAAm-grafted PHBV mat compared with film. With porous mats, the water molecules easily reach to grafted PIPAAm from underneath and peripheral to the attached cells, resulting in rapid hydration of grafted PIPAAm molecules and detachment of the cells.

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Chen, Zi Ye, Ze Xu Hu, Heng Xue Xiang, Wei Chen, Zhang Gen Ni, and Mei Fang Zhu. "Crystallization Behavior of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) with WS₂ as Nucleating Agent." Materials Science Forum 898 (June 2017): 2239–45. http://dx.doi.org/10.4028/www.scientific.net/msf.898.2239.

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Poly (3-hydroxybutyrate-co-hydroxyvalerate) (PHBV) is one of the aliphatic polyesters that are completely synthesized by microorganisms. Owing to the physical and chemical properties of PHA being similar with those of polypropylene, PHBV is expected to be able to partially replace petroleum-based polymers, and to reduce the pollution of environment at the same time. However, many inherent defects, including slow crystallization rate, large-size spherulite and secondary crystallization phenomenon, restrict the development of PHBV. In the present study, PHBV/WS2 hybrid materials where the tungsten disulphide (WS2) acted as nucleating agent were produced, and then its accelerated crystallization effect on PHBV was evaluated. Mo’s methods were employed to describe the non-isothermal crystallization kinetics of the nucleated PHBV hybrid materials. The activation energy (ΔE) of hybrid material was calculated by Kissinger formula. It was found that the addition of low WS2 loadings strongly increased the crystallization rate of PHBV and correspondingly the crystallization half time (t1/2) decreased from 97s to 38s with only 1wt.% WS2 added. Meanwhile, the crystallization temperature (Tc) increased from 81.9°C to 112 °C. The results reported here are expected to be of great interest for the practical application of PHBV.

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Gasmi, S., M. K. Hassan, and A. S. Luyt. "Crystallization and dielectric behaviour of PLA and PHBV in PLA/PHBV blends and PLA/PHBV/TiO2 nanocomposites." Express Polymer Letters 13, no. 2 (2019): 199–212. http://dx.doi.org/10.3144/expresspolymlett.2019.16.

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Duangphet, Sitthi, Damian Szegda, Karnik Tarverdi, and Jim Song. "Effect of Calcium Carbonate on Crystallization Behavior and Morphology of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)." Key Engineering Materials 751 (August 2017): 242–51. http://dx.doi.org/10.4028/www.scientific.net/kem.751.242.

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The effects of calcium carbonate (CaCO3) concentration on crystallization behaviors and morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were investigated. Composites of PHBV with CaCO3 were prepared with filler loadings of low (5%wt) and high concentration (20%wt) and these were subsequently compared to unloaded PHBV. The morphologies of PHBV composites on the freeze-fractured specimens were examined using scanning electron microscopy (SEM). The SEM images revealed that increasing concentration of CaCO3 resulted in agglomeration. This agglomeration might affect crystal growth rate and mechanism. The crystal growth behavior of melt-crystallized PHBV with different amounts of CaCO3 was studied by polarized optical microscopy (POM), while the crystal structure was examined by X-ray diffraction (XRD). The rate of crystal growth determined from POM at selected crystallization temperatures revealed that the addition of a small amount of CaCO3 accelerated crystal growth rate, whereas excess amount of CaCO3 had the opposite effect. The POM images were also used to illustrate the change of crystal growth process presence of CaCO3. The unloaded PHBV clearly showed nucleation and growth mechanism, while PHBV composites displayed nucleation and then combination of crystals during the growth process. However, CaCO3 did not affect the crystal structureof any PHBV composite as observed by XRD. Molecular weight determination via gel permeation chromatography (GPC) indicated that there was no significant difference among PHBV composites.

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Chotchindakun, Kittipat, Jeeraporn Pekkoh, Jetsada Ruangsuriya, Kai Zheng, Irem Unalan, and Aldo R. Boccaccini. "Fabrication and Characterization of Cinnamaldehyde-Loaded Mesoporous Bioactive Glass Nanoparticles/PHBV-Based Microspheres for Preventing Bacterial Infection and Promoting Bone Tissue Regeneration." Polymers 13, no. 11 (May 29, 2021): 1794. http://dx.doi.org/10.3390/polym13111794.

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Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is considered a suitable polymer for drug delivery systems and bone tissue engineering due to its biocompatibility and biodegradability. However, the lack of bioactivity and antibacterial activity hinders its biomedical applications. In this study, mesoporous bioactive glass nanoparticles (MBGN) were incorporated into PHBV to enhance its bioactivity, while cinnamaldehyde (CIN) was loaded in MBGN to introduce antimicrobial activity. The blank (PHBV/MBGN) and the CIN-loaded microspheres (PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20) were fabricated by emulsion solvent extraction/evaporation method. The average particle size and zeta potential of all samples were investigated, as well as the morphology of all samples evaluated by scanning electron microscopy. PHBV/MBGN/CIN5, PHBV/MBGN/CIN10, and PHBV/MBGN/CIN20 significantly exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli in the first 3 h, while CIN releasing behavior was observed up to 7 d. Human osteosarcoma cell (MG-63) proliferation and attachment were noticed after 24 h cell culture, demonstrating no adverse effects due to the presence of microspheres. Additionally, the rapid formation of hydroxyapatite on the composite microspheres after immersion in simulated body fluid (SBF) during 7 d revealed the bioactivity of the composite microspheres. Our findings indicate that this system represents an alternative model for an antibacterial biomaterial for potential applications in bone tissue engineering.

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Wang, Kun Yan, and Feng Cao. "Effect of Organoclay on Thermal Degradation and Crystalline Morphology Properties of Biodegradable PHBV." Advanced Materials Research 791-793 (September 2013): 256–59. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.256.

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Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/organoclay blends were prepared by solution blend method. The effect of organoclay on the thermal degradation and crystalline morphology properties were studied by thermogravimetry (TG)X-ray diffraction (XRD) and polarizing optical microscopy (POM) analyses. TG results indicates better processability of the blends with 5wt% organoclay than that of pure PHBV. XRD results show that the organoclay does not modify the crystal structure in the blends but only increase the intensity of diffraction peak. PHBV and PHBV/organoclay revealed integrated Maltese crossed spherulitic morphologies. While small-sized PHBV spherulites were formed when organoclay added to PHBV.

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Yang, Song, Yue-Yi Wang, Ying-Nan Song, Li-Chuan Jia, Gan-Ji Zhong, Ling Xu, Ding-Xiang Yan, Jun Lei, and Zhong-Ming Li. "Ultrathin, flexible and sandwich-structured PHBV/silver nanowire films for high-efficiency electromagnetic interference shielding." Journal of Materials Chemistry C 9, no. 9 (2021): 3307–15. http://dx.doi.org/10.1039/d0tc05266c.

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An ultrathin transparent EMI shielding film with sandwich structure including PHBV, AgNWs and PHBV was fabricated. The AgNW layer encapsulated with PHBV can endow the film with high EMI effectiveness and environment stability.

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Oprică, Mădălina Gabriela, Cătălina Diana Uşurelu, Adriana Nicoleta Frone, Augusta Raluca Gabor, Cristian-Andi Nicolae, Valentin Vasile, and Denis Mihaela Panaitescu. "Opposite Roles of Bacterial Cellulose Nanofibers and Foaming Agent in Polyhydroxyalkanoate-Based Materials." Polymers 14, no. 24 (December 7, 2022): 5358. http://dx.doi.org/10.3390/polym14245358.

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In this work, an economically feasible procedure was employed to produce poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based foams. Thermally expandable microspheres (TESs) were used as a blowing agent, while bacterial cellulose (BC) nanofibers served both as a reinforcing agent and as a means of improving biocompatibility. PHBV was plasticized with acetyltributylcitrate to reduce the processing temperature and ensure the maximum efficiency of the TES agent. The morphological investigation results for plasticized PHBV foams showed well-organized porous structures characterized by a porosity of 65% and the presence of both large pores (>100 µm) and finer ones, with a higher proportion of pores larger than 100 µm being observed in the PHBV nanocomposite containing TESs and BC. The foamed structure allowed an increase in the water absorption capacity of up to 650% as compared to the unfoamed samples. TESs and BC had opposite effects on the thermal stability of the plasticized PHBV, with TESs decreasing the degradation temperature by about 17 °C and BC raising it by 3–4 °C. A similar effect was observed for the melting temperature. Regarding the mechanical properties, the TESs had a flexibilizing effect on plasticized PHBV, while BC nanofibers showed a stiffening effect. An in vitro cytotoxicity test showed that all PHBV compounds exhibited high cell viability. The addition of TESs and BC nanofibers to PHBV biocomposites enabled balanced properties, along with lower costs, making PHBV a more attractive biomaterial for engineering, packaging, or medical device applications.

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Wu, Yuandong, Weishuang Zheng, Yinan Xiao, Beining Du, Xingru Zhang, Min Wen, Chen Lai, Yi Huang, and Liyuan Sheng. "Multifunctional, Robust, and Porous PHBV—GO/MXene Composite Membranes with Good Hydrophilicity, Antibacterial Activity, and Platelet Adsorption Performance." Polymers 13, no. 21 (October 29, 2021): 3748. http://dx.doi.org/10.3390/polym13213748.

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The limitations of hydrophilicity, strength, antibacterial activity adsorption performance of the biobased and biocompatible polymer materials, such as polyhydroxyalkanoates (PHAs), significantly restrict their wider applications especially in medical areas. In this paper, a novel composite membrane with high antibacterial activity and platelet adsorption performance was prepared based on graphene oxide (GO), MXene and 3-hydroxybutyrate-co-hydroxyvalerate (PHBV), which are medium-chain-length-copolymers of PHA. The GO/MXene nanosheets can uniformly inset on the surface of PHBV fibre and give the PHBV—GO/MXene composite membranes superior hydrophilicity due to the presence of hydroxyl groups and terminal oxygen on the surface of nanosheets, which further provides the functional site for the free radical polymerization of ester bonds between GO/MXene and PHBV. As a result, the tensile strength, platelet adsorption, and blood coagulation time of the PHBV—GO/MXene composite membranes were remarkably increased compared with those of the pure PHBV membranes. The antibacterial rate of the PHBV—GO/MXene composite membranes against gram-positive and gram-negative bacteria can reach 97% due to the antibacterial nature of MXene. The improved strength, hydrophilicity, antibacterial activity and platelet adsorption performance suggest that PHBV—GO/MXene composite membranes might be ideal candidates for multifunctional materials for haemostatic applications.

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Nachod, Benjamin, Emily Keller, Amro Hassanein, and Stephanie Lansing. "Assessment of Petroleum-Based Plastic and Bioplastics Degradation Using Anaerobic Digestion." Sustainability 13, no. 23 (December 1, 2021): 13295. http://dx.doi.org/10.3390/su132313295.

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Bioplastics have emerged as a viable alternative to traditional petroleum-based plastic (PET). Three of the most common bioplastic polymers are polyhydroxybutyrate-valerate (PHBV), polylactide (PLA), and cellulose-based bioplastic (CBB). This study assessed biodegradation through anaerobic digestion (AD) of these three bioplastics and PET digested with food waste (FW) at mesophilic (35 °C) and thermophilic (55 °C) temperatures. The four plastic types were digested with FW in triplicate batch reactors. Additionally, two blank treatments (inoculum-only) and two PHBV treatments (with FW + inoculum and inoculum-only) were digested at 35 and 55 °C. The PHBV treatment without FW at 35 °C (PHBV-35) produced the most methane (CH4) normalized by the volatile solids (VS) of the bioplastics over the 104-day experimental period (271 mL CH4/g VS). Most bioplastics had more CH4 production than PET when normalized by digester volume or gram substrate added, with the PLA-FW-55 (5.80 m3 CH4/m3), PHBV-FW-55 (2.29 m3 CH4/m3), and PHBV-55 (4.05 m3 CH4/m3) having 848,275 and 561%, respectively, more CH4 production than the PET treatment. The scanning electron microscopy (SEM) showed full degradation of PHBV pellets after AD. The results show that when PHBV is used as bioplastic, it can be degraded with energy production through AD.

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Chotchindakun, Kittipat, Wasu Pathom-Aree, Kanchana Dumri, Jetsada Ruangsuriya, Chayakorn Pumas, and Jeeraporn Pekkoh. "Low Crystallinity of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) Bioproduction by Hot Spring Cyanobacterium Cyanosarcina sp. AARL T020." Plants 10, no. 3 (March 8, 2021): 503. http://dx.doi.org/10.3390/plants10030503.

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The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from cyanobacteria is an environmentally friendly biodegradable polymer. The low yield of PHBV’s production is the main hindrance to its sustainable production, and the manipulation of PHBV production processes could potentially overcome this obstacle. The present research investigated evolutionarily divergent cyanobacteria obtained from local environments of Thailand. Among the strains tested, Cyanosarcina sp. AARL T020, a hot spring cyanobacterium, showed a high rate of PHBV accumulation with a fascinating 3-hydroxyvalerate mole fraction. A two-stage cultivation strategy with sole organic carbon supplementation was successful in maximizing cyanobacterial PHBV production. The use of an optimized medium in the first stage of cultivation provided a 4.9-fold increase in biomass production. Subsequently, the addition of levulinic acid in the second stage of cultivation can induce significant biomass and PHBV production. With this strategy, the final biomass production and PHBV productivity were increased by 6.5 and 73.2 fold, respectively. The GC-MS, FTIR, and NMR analyses confirmed that the obtained PHBV consisted of two subunits of 3-hydroxyvaryrate and 3-hydroxybutyrate. Interestingly, the cyanobacterial PHBV contained a very high 3-hydroxyvalerate mole fraction (94%) exhibiting a low degree of crystallinity and expanding in processability window, which could be applied to polymers for desirable advanced applications.

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Sultana, Naznin, and Min Wang. "In Vitro Degradation and Protein Adsorption Characteristics of PHBV/PLLA Blends and PHBV/PLLA-Based Tissue Engineering Scaffolds." Advanced Materials Research 47-50 (June 2008): 1399–402. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.1399.

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Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) was used to make composite scaffolds for bone tissue engineering in our previous studies. To control the degradation rate and process of composite scaffolds, PHBV was blended with poly(L-lactic acid) (PLLA), which has a much higher degradation rate than PHBV, and PHBV/PLLA blends were used as polymer matrices for composite scaffolds. Composite scaffolds based on these blends and containing nano-sized hydroxyapatite (nHA) were fabricated using an emulsion freezing / freeze-drying technique. Non-porous films of PHBV/PLLA blends were prepared using the solvent casting method. In vitro degradation tests of non-porous PHBV/PLLA blends and porous composite scaffolds were conducted by immersing samples in phosphate buffered saline (PBS) for various periods of time. It was found that the composition of polymer blends affected water uptake of films and scaffolds. For PHBV/PLLA-based scaffolds, the incorporated nHA particles also significantly increased water uptake within the initial immersion time. Both PHBV/PLLA blends and composite scaffolds underwent rapid weight losses within the first few weeks. The degradation of composite scaffolds arose from the dissolution of nHA particles and degradation of the PLLA component of polymer blends. Composite scaffolds exhibited enhanced adsorption of bovine serum albumin (BSA), a model protein, in the current study.

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Duangphet, Sitthi, Damian Szegda, Karnik Tarverdi, and Jim Song. "The Effect of Poly(Butylene Adipate-co-Terephthalate) on Crystallization Behavior and Morphology of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate)." Key Engineering Materials 798 (April 2019): 343–50. http://dx.doi.org/10.4028/www.scientific.net/kem.798.343.

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The effects of poly(butylene adipate-co-terephthalate) (PBAT) on crystallization behavior and morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were studied to provide the useful information to control and improve PHBV processing. PHBV were blended with 15, 30 and 50 wt% PBAT by twin screw extrusion and these were subsequently compared to unblended PHBV. The rate of crystal development determined from differential scanning calorimetry (DSC) at 120 °C showed that the incorporation of PBAT retarded the crystal growth rate. Moreover, the crystal structure of polymer blends was examined by X-ray diffraction (XRD) and the results revealed that PBAT did not affect the crystal structure of PHBV. The responses of the melt-crystallized PHBV to different quantities of PBAT were recorded by polarized optical microscopy (POM). The results demonstrated that the size of spherulite dramatically increased when 15 wt% PBAT was added and the shape of spherulite was imperfect when PBAT reached 30 wt%. The morphologies of PHBV and its blends on the freeze-fractured specimens were exposed using scanning electron microscopy (SEM). The SEM images revealed the phase separation of PHBV/ PBAT blends in any composition. The morphology of 15 and 30 wt% PBAT presented droplet in matrix morphology and changed to co-continuous morphology at 50 wt% PBAT.

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Chutamas, Maneewong, Sunthornvarabhas Jackapon, Joong Kim Hyun, and Sriroth Klanarong. "Improving Mechanical Properties of Poly-β-Hydroxybutyrate-co-β-Hydroxyvalerate by Blending with Natural Rubber and Epoxidized Natural Rubber." Advanced Materials Research 983 (June 2014): 179–82. http://dx.doi.org/10.4028/www.scientific.net/amr.983.179.

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Poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV) is a bacterial-synthesized biopolymer. Moreover, PHBV is a biodegradable, it is an interesting biopolymer for disposable products. PHBV is difficult to process due to its low toughness, an elastic polymer such as natural rubber is introduced to develop toughness. In this experiment, PHBV mechanical properties were improved by blending with natural rubber (NR) and epoxidized natural rubber (ENR). The NR/PHBV and ENR/PHBV blends with the same ratio of 10/90 (wt/wt) could be extruded, whereas other conditions could not. This ratio was then used throughout this study to examine effect of maleic anhydride (MA) and benzoyl peroxide (BPO) to improve toughness of the blends. Result showed at composition where 1.0 % (wt/wt) MA and 0.05 % (wt/wt) BPO was mixed (coding EPMB2), several aspects of mechanical properties were improved. The blend, EPMB2 revealed the highest impact strength, significantly improved of elongation but drastically decreased of tensile strength. Storage modulus slightly decreased, tangent delta significantly increased when compared with neat PHBV.

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Wang, Kun Yan. "Peroxide Induced Reaction as a Cross-Linking Method in PHBV Biomaterial Gate Dielectrics." Key Engineering Materials 777 (August 2018): 75–79. http://dx.doi.org/10.4028/www.scientific.net/kem.777.75.

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A peroxide induced reaction was applied as a cross-linking method for Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biomaterial gate dielectrics. PHBV was effectively cross-linked with a peroxide inducer at a relatively low temperature (90°C). The cross-linked microstructures improve the thermal stability compared with uncross-linked PHBV. This peroxide induced cross-linking method was compatible with plastic substrates for flexible electronic applications. The cross-linked PHBV thin films displayed smooth surfaces.

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Antunes, Ana, Anton Popelka, Omar Aljarod, Mohammad K. Hassan, Peter Kasak, and Adriaan S. Luyt. "Accelerated Weathering Effects on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV/TiO2 Nanocomposites." Polymers 12, no. 8 (August 5, 2020): 1743. http://dx.doi.org/10.3390/polym12081743.

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The effect of accelerated weathering on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV-based nanocomposites with rutile titanium (IV) dioxide (PHBV/TiO2) was investigated. The accelerated weathering test applied consecutive steps of UV irradiation (at 340 nm and 0.76 W m−2 irradiance) and moisture at 50 °C following the ASTM D4329 standard for up to 2000 h of exposure time. The morphology, chemical structure, crystallization, as well as the mechanical and thermal properties were studied. Samples were characterized after 500, 1000, and 2000 h of exposure time. Different degradation mechanisms were proposed to occur during the weathering exposure and were confirmed based on the experimental data. The PHBV surface revealed cracks and increasing roughness with the increasing exposure time, whereas the PHBV/TiO2 nanocomposites showed surface changes only after 2000 h of accelerated weathering. The degradation of neat PHBV under moisture and UV exposure occurred preferentially in the amorphous phase. In contrast, the presence of TiO2 in the nanocomposites retarded this process, but the degradation would occur simultaneously in both the amorphous and crystalline segments of the polymer after long exposure times. The thermal stability, as well as the temperature and rate of crystallization, decreased in the absence of TiO2. TiO2 not only provided UV protection, but also restricted the physical mobility of the polymer chains, acting as a nucleating agent during the crystallization process. It also slowed down the decrease in mechanical properties. The mechanical properties were shown to gradually decrease for the PHBV/TiO2 nanocomposites, whereas a sharp drop was observed for the neat PHBV after an accelerated weathering exposure. Atomic force microscopy (AFM), using the amplitude modulation–frequency modulation (AM–FM) tool, also confirmed the mechanical changes in the surface area of the PHBV and PHBV/TiO2 samples after accelerated weathering exposure. The changes in the physical and chemical properties of PHBV/TiO2 confirm the barrier activity of TiO2 for weathering attack and its retardation of the degradation process.

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Chutamas, Maneewong, Sunthornvarabhas Jackapon, and Klana Rong Sriroth. "Evaluation of Gamma Radiation on NR/PHBV Blends." Applied Mechanics and Materials 300-301 (February 2013): 1325–29. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.1325.

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Natural rubber (NR) was compounded with polyhydroxybutyrate-co-hydroxyvalerate (PHBV) to improve mechanical properties for making a composite to be used in packaging applications. Gamma radiation technique was used to improve adhesion properties between these materials. The results showed that gamma radiation could induce cross-linking between NR and PHBV. The SEM micrograph illustrated the radiated NR/PHBV blends with gamma dose 5 kGy, 10 kGy and 15 kGy presenting a good adhesion at the blend interface. The investigation by FTIR, showing the appearance of small peaks at 2950 and 2997 cm-1 related to CH3 asymmetric stretching, also confirmed the cross-linking after the exposure of the NR/PHBV blend to gamma radiation. Also, the tensile results supported cross-linking between NR and PHBV. The elongation at break of NR/PHBV blend decreased when increasing dosage of gamma ray from 0 kGy to 15 kGy.

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ZHANG, QINGSONG, YIPING ZHAO, and LI CHEN. "EFFECT OF PHBV CONTENT ON THE TRANSPARENCY AND SWELLING BEHAVIOR OF POLYMER/HECTORITE NANOCOMPOSITE HYDROGEL." International Journal of Modern Physics B 23, no. 06n07 (March 20, 2009): 1365–70. http://dx.doi.org/10.1142/s0217979209060956.

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As a kind of novel biopolymer material with good biodegradability and biocompatibility, poly(β-hydroxybutyrate-co-valerate)(PHBV) was introduced into organic/inorganic network structure of nanocomposite hydrogels prepared by in-situ free-radical polymerization based on monomer N-isopropylacrylamide(NIPAM) and physical cross-linker hectorite. As viewed from appearance of the hydrogels, obvious change occurred from transparent to white with the increase of PHBV content, which reflects the structural shift from homogeneity to inhomogeneity. The swelling ratio and swelling kinetics of thermo-sensitive poly( NIPAM / PHBV /Hectorite) hydrogels with different PHBV content was investigated by gravimetric method. It was found that the incorporation of PHBV decreases the swelling ratio of pure poly( NIPAM /Hectorite) hydrogels on account of hydrophobicity of PHBV . Furthermore, in the case of swelling kinetics, the result of linear regression shows that relaxation of polymer chains of the hydrogels controls the swelling process.

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Tomano, N., O. Boondamnoen, C. Aumnate, and P. Potiyaraj. "Development of green materials from ENR-25/PHBV blends: Curing characteristics and mechanical performance." Journal of Physics: Conference Series 2175, no. 1 (January 1, 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2175/1/012026.

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Abstract The objective of this work was to develop green materials from epoxidized natural rubber (25% epoxidation), (ENR-25), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), (PHBV), and polybutadiene adducted with maleic anhydride, (PB-g-MA) as compatibilizer. The ENR-25/PHBV blends were prepared at the ratio of 100/0, 90/10, and 80/20 with 0 and 10 %wt. PB-g-MA. The blends were prepared using an internal mixer, where PHBV was first melted at a temperature of 175 °C before mixing with ENR-25 and the incorporation of a compatibilizer. The mixing of ENR-25 and PHBV was continued at a temperature of 175 °C and mixing speed of 50 rpm until it reaches the complete blending time. All ENR-25/PHBV blends were then mixed with curing agents in an internal mixer at a temperature of 50 °C. The cure characteristics were determined using a moving die rheometer (MDR). Then vulcanization proceeded in a compression molding machine. The result shows that the addition of PHBV enhanced the modulus of ENR-25 for every blend ratio with and without compatibilizer owing to the mechanical properties of PHBV. Significantly, the PB-g-MA compatibilizer successfully improved the interface adhesion between ENR-25 and PHBV and the decrease in phase size was clearly seen in the SEM images.

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Journal articles on the topic 'PHBV'

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