Properties Enhancement of Polylactic Acid Biocomposite

Natural rubber toughened by polylactic acid/graphene (PLA/NR/GR) biocomposite was prepared by two different processes known as the in-situ melt mixing process (conventional) and the integration of latex compounding masterbatch and melt mixing process. These two processes were employed to compare the state of graphene dispersion and distribution in the biocomposite. Good dispersion and distribution of nanographene is a key factor that can enhance or change the properties of the nanocomposite. The objectives of this work are to evaluate the effect of different processes and graphene content on the mechanical, and morphological of PLA/NR/GR biocomposites. The composition of PLA/NR blend was fixed at 80/20 wt% and the graphene content was varied from 0.1 - 0.4 parts per hundred (phr). The integration process produced the PLA/NR/GR nanocomposite with better mechanical properties compared with the conventional process due to a better state of GR dispersion in the nanocomposite. The tensile strength was slightly improved at lower GR content indicating that GR is effective in increasing strength of toughened PLA nanocomposite. NR improved the impact strength of PLA biocomposites with a sacrifice of tensile strength. The results also revealed that the PLA/NR blend was reinforced and toughened simultaneously by GR, which is extraordinary as compared with many reported nanofiller-reinforced PLA composites. The simultaneous improvement in both strength and toughness could be attributed to the homogeneous dispersion of GR in PLA/NR matrix. The integration process had given a promising method to homogeneously dispersed GR in the polymer matrix which in turn can become a successful method for producing graphene nanocomposite.