Preparation and Properties of Kenaf Bast Fiber Filled Poly(lactic Acid) [plasticized] Composite

Kenaf bast fiber (KBF) filled plasticized poly(lactic acid) (p-PLA) composites was prepared and examined stage by stage in this study. Firstly, poly(lactic acid) (PLA) was plasticized with 5 up to 20 wt% poly(ethylene glycol) (PEG) via internal mixer. Blend with 10 wt% PEG was chosen as matrix for composite as it showed the best impact strength and elongation at break. Secondly, maleic anhydride grafted PLA (MAPLA) was successfully produced with 0.22% grafting using reactive grafting method, and used as a compatibilizer for the composite system. p-PLA/KBF composite was compounded via internal mixer and compression molded into test specimens. KBF loading was varied from 10 to 40 wt%. Characterization was done by means of tensile and impact testing, dynamic mechanical analysis, water absorption, soil burial and natural weathering. At 40 wt% KBF loading, tensile strength and modulus improved by 120% and 213% respectively, while strain at break and impact strength dropped by 99% and 52% respectively compared to neat p-PLA. Improvement in properties suggests effective stress transfer between fiber and matrix. Morphological studies leads to assumption that PEG interrupts the interaction between KBF and PLA, forming undesirable interphase. Tensile strength and modulus dropped while strain at break improved when 5 wt% MAPLA was added to the composite systems. MAPLA is believed to interact with PEG instead of KBF, enhancing the plasticization effect instead of performing as a compatibilizer for the composite system. Tensile strength and modulus improved only when 10 wt% MAPLA was added to 40 wt% KBF