Morphological, Thermal and Mechanical Properties of Epoxidized Soil Bean Plasticized Polylactic Acid/Graphene Nanocomposites

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Buncha Suksut
Thanyamas Huayhongtong
Kanokwon Mangkang
Weerapat Saisuwan


Due to their biodegradability, both polylactic acid (PLA) and epoxidized soil bean (ESO) were blended at various contents of ESO (3-10 wt%) by melt blending in an internal mixer. Inclusion of 10 wt% of ESO into PLA showed the highest elongation at break and the impact strength. The incorporation of graphene (GP) into PLA/ESO blend promoted the impact strength of the composites accompanied by lowering stiffness and strength. From DSC analysis, the glass transition temperature (Tg) decreased, while the degree of crystallinity of PLA increased with the inclusion of ESO. Crystallization temperature (Tc) of PLA at 10 wt% of ESO decreased about 10°C in comparison with neat PLA. However, the presence of GP has no significant effect on any transition temperatures of PLA, but led to smaller spherulite size. The resulting performances of the plasticized PLA composite were explained by two possibilities, the interfacial adhesion between PLA matrix and GP particles as well as the competitive effect of ESO and GP on PLA crystallization.

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