Synergistic improvements in the impact strength and % elongation of polyhydroxybutyrate-co-valerate copolymers with functionalized soybean oils and POSS (original) (raw)
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Polymer International, 2016
The effect of different epoxidized vegetable oils (EVOs) as potential plasticizers for poly(3-hydroxybutyrate), PHB was evaluated in terms of changes in mechanical and thermal properties and morphology. PHB is a biodegradable aliphatic polyester obtained from bacterial fermentation. High stiffness and fragility are two of its main drawbacks. To overcome this behavior PHB was plasticized with various amounts of two different epoxidized vegetable oils: epoxidized linseed oil (ELO) and epoxidized soybean oil (ESBO). The total ELO and ESBO content varied in the 5 phr (per hundred resin)-20 phr range and plasticized PHB materials were obtained by melt extrusion and compounding followed by injection molding. The results show that the plasticizing effect provided by ELO is more efficient than ESBO with balanced properties at a concentration of 10 phr ELO. ELO addition leads to an improvement on mechanical ductile properties with a noticeable increase in elongation at break and impact absorbed energy. With regard to thermal properties, both the addition of ELO and ESBO leads to a remarkable increase in thermal stability of PHB. All these findings suggest that addition of 10 phr ELO leads to optimized PHB formulations with potential uses in technical applications.
Polymer International, 2016
The effect of different epoxidized vegetable oils (EVOs) as potential plasticizers for poly(3-hydroxybutyrate), PHB was evaluated in terms of changes in mechanical and thermal properties and morphology. PHB is a biodegradable aliphatic polyester obtained from bacterial fermentation. High stiffness and fragility are two of its main drawbacks. To overcome this behavior PHB was plasticized with various amounts of two different epoxidized vegetable oils: epoxidized linseed oil (ELO) and epoxidized soybean oil (ESBO). The total ELO and ESBO content varied in the 5 phr (per hundred resin)-20 phr range and plasticized PHB materials were obtained by melt extrusion and compounding followed by injection molding. The results show that the plasticizing effect provided by ELO is more efficient than ESBO with balanced properties at a concentration of 10 phr ELO. ELO addition leads to an improvement on mechanical ductile properties with a noticeable increase in elongation at break and impact absorbed energy. With regard to thermal properties, both the addition of ELO and ESBO leads to a remarkable increase in thermal stability of PHB. All these findings suggest that addition of 10 phr ELO leads to optimized PHB formulations with potential uses in technical applications.
Macromolecular Materials and Engineering, 2016
Poly(3-hydroxybutyrate), P3HB is a thermoplastic polyester synthesized from bacterial fermentation with potential uses in packaging due to its biodegradability. Nevertheless, P3HB is a fragile material and its processing temperature window is very narrow which restricts its use. This study explores the potential of vegetable oil-derived plasticizers, i.e., maleinized linseed oil (MLO) and an epoxidized fatty acid ester (EFAE) in the 5-20 phr range as environmentally friendly solutions for P3HB industrial formulations with improved toughness. The results show that optimum balance between ductile properties is achieved with low plasticizer content (5 phr) for both plasticizer types. Elongation at break and the impact resistance are increased by 28 and 71% respectively after addition of 5 phr MLO. With regard to EFAE, the elongation at break is improved by 40% and the impact resistance is increased to twice the value of P3HB. Another effect that both plasticizers provide is the thermal stabilization with a delay in the onset degradation temperature.
Chemical engineering transactions, 2021
Poly(hydroxybutyrate-co-valerate) (PHBV), a biodegradable thermoplastic polymer, has attracted much attention because of increasing interest in protection of environment. PHBV is brittle, thus has restricted application. Improvement of its toughness has been attempted by blending poly (caprolactone (PCL). In this study, PCL helps in improving elongation at break and impact properties of PHBV. PHBV/PCL blends were blended using internal mixer. Differential scanning calorimetry (DSC) was used to determine the thermal properties of the blends and tensile and impact test for the mechanical test of the blends. There are two melting peaks shown in the DSC data of PHBV/PCL due to melting of PHBV and PCL. 60/40 ratio of PHBV/PCL was chosen as the optimum composition as it showed the highest elongation at break with 4.2 % improvement compared to pure PHBV. This blend ratio also has the lowest melting temperature of PHBV among ratio studied. Although the properties of PHBV/PCL blends were bet...
Journal of Polymers and the Environment, 2020
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-V) has not been used for demanding technical applications yet due to its limited mechanical properties, particularly its high brittleness. An appropriate route to overcome these limitations is the implementation of plasticizers in the PHB-V matrix via compounding. In this paper the use of different types of fatty acids esters as PHB-V plasticizers were investigated. The study describes how the difference in the fatty acid esters structure (mainly fatty acid hydrocarbon chain length) affects their plasticizing effect and thus the PHB-V ductility performance. The best impact properties of PHB-V compounds were obtained for oleic acid methyl ester, palmitic acid methyl ester or lauric acid ethylene glycol monoester. The increase of notched impact strength from 1.4 (for neat polymer) to 4.0–4.1 kJ/m 2 was observed. At the same time stiffness and strength of the polymer decreased but remain on a level sufficient for technical applications....
Polymerization of epoxidized soybean oil with maleinized polybutadiene
Journal of Applied Polymer Science, 2010
In this study, maleinized soybean oil triglycerides (SOMA) were reacted with epoxidized soybean oil triglycerides (ESO) to give plant oil-based thermoset polymers. To increase fracture toughness of the product, different amounts of SOMA was replaced by maleic anhydride grafted polypropylene (MMPP) (Epolene E43, maleate content 2.9%, M n ¼ 3900 and Polybond 3200, maleate content 1%, M n ¼ 1,10,000). The improvement in mechanical properties was monitored. The characterizations of the products were done by DMA, DSC, TGA, and IR spectroscopy. ESO-SOMA and ESO-SOMA-MMPP polymers are crosslinked rigid infusible polymers. ESO-SOMA-MMPP(E43) and ESO-SOMA-MMPP(PB3200) showed a phase change at 146 and 169 C, respectively, probably due to the melting transition of the MMPP backbone. Storage moduli of the two polymers at 35 C were 54.6 and 246.1 MPa, respectively. Storage moduli and the impact strength of the polymers increased with MMPP content and with MMPP molecular weight.
Macromolecules, 2016
Polylactide (PLA), a commercially available thermoplastic derived from plant sugars, finds applications in consumer products, disposable packaging, and textiles, among others. The widespread application of this material is limited by its brittleness, as evidenced by low tensile elongation at break, impact strength, and fracture toughness. Herein, a multifunctional vegetable oil, acrylated epoxidized soybean oil (AESO), was investigated as a biodegradable, renewable additive to improve the toughness of PLA. AESO was found to be a highly reactive oil, providing a dispersed phase with tunable properties in which the acrylate groups underwent cross-linking at the elevated temperatures required for processing the blends. Additionally, the presence of hydroxyl groups on AESO provided two routes for compatibilization of PLA/AESO blends: (1) reactive compatibilization through the transesterification of AESO and PLA and (2) synthesis of a PLA star polymer with an AESO core. The morphological, thermal, and mechanical behaviors of PLA/oil blends were investigated, in which the dispersed oil phase consisted of AESO, soybean oil (SYBO), or a 50/50 mixture of AESO/SYBO. The oil additives were found to toughen the PLA matrix, with significant enhancements in the elongation at break and tensile toughness values, while maintaining the glass transition temperature of neat PLA. In particular, the blend containing PLA, AESO, SYBO, and the PLA star polymer was found to exhibit a uniform oil droplet size distribution with small average droplet size and interparticle distance, resulting in the greatest enhancements of PLA tensile properties with no observable plasticization.
Polymers, 2019
Two major obstacles to utilizing polyhydroxybutyrate (PHB)—a biodegradable and biocompatible polymer—in commercial applications are its low tensile yield strength (<10 MPa) and elongation at break (~5%). In this work, we investigated the modification of the mechanical properties of PHB through the use of a variety of bio-derived additives. Poly(lactic acid) (PLA) and sugarcane-sourced cellulose nanocrystals (CNCs) were proposed as mechanical reinforcing elements, and epoxidized canola oil (eCO) was utilized as a green plasticizer. Zinc acetate was added to PHB and PLA blends in order to improve blending. Composites were mixed in a micro-extruder, and the resulting filaments were molded into 2-mm sheets utilizing a hot-press prior to characterization. The inclusion of the various additives was found to influence the crystallization process of PHB without affecting thermal stability. In general, the addition of PLA and, to a lesser degree, CNCs, resulted in an increase in the Young...