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Polylactic acid (PLA) is one of the biodegradable polymer that is widely used in many applications to replace petroleum-based polymer. Despite the advantages of PLA, its disadvantages such as poor toughness and brittleness restrict the usage of PLA. The purpose of this study is to improve the properties of PLA by blending with liquid epoxidized natural rubber (LENR) and graphene oxide (GO). Two different samples were prepared which were PLA/LENR/GO and PLA/GO grafted LENR (PLA/GO-g-LENR) composites. GO-g-LENR was prepared by using grafting method. The materials were blended by using Brabender internal mixer with rotor speed of 60 rpm at 160 °C. The GO content was varied from 1, 3 and 5 phr while the composition of LENR was fixed at 10 wt%. After blending, the compound was compressed into a plate under hot pressing machine then was cut according to ASTM D256 for characterization. The properties of the composites were investigated in term of mechanical, thermal and morphological aspects. Fourier transform infrared (FTIR) analysis was used to confirm the efficiency of grafting method. The addition of 1 phr GO using GO-g-LENR into PLA composite showed the highest impact strength which is 96.02 J/m while 1 phr GO without grafting increased the impact strength from 86.05 J/m to 91.42 J/m. Thermal analysis study by TGA indicated that addition of GO into the composite system has improved its thermal stability. Morphological study revealed that 1 phr GO has better dispersion in PLA/LENR matrix compared to 3 phr GO.

Polylactic acid (PLA) is a potential polymer to be used in various applications due to biodegradable and biocompatible characteristics. However, its brittle nature limits the usage of PLA. In order to improve the brittleness of PLA, liquid epoxidized natural rubber (LENR) was incorporated with PLA. The objective of this study is to investigate the effect of LENR as toughening agent on rigid PLA matrix in term of mechanical and thermal properties. Polylactic acid/liquid epoxidized natural rubber (PLA/LENR) blends were prepared by melt blending method using Brabender internal mixer with temperature 160 ?, mixing speed of 60 rpm and molded into test samples by compression molding. The LENR content was varied from 0, 5, 10, 15 and 20 wt%. It was found that the addition of LENR increased the impact strength of PLA.10 wt% of LENR showed the optimum impact strength which was 86.05 J/m. However, tensile strength and tensile modulus decreased slightly with increasing of LENR content. The morphology of PLA/LENR blends showed a good dispersion of LENR on PLA matrix at 10 wt% LENR. The differential scanning calorimeter (DSC) showed a gradual drop in melting temperature (Tm) as well as glass transition temperature (Tg) as LENR content increased.