Mechanical and Morphological Properties of Polylactic Acid/Kenaf Bast Fiber Composites Toughened with an Impact Modifier

Polylactic acid (PLA)/kenaf bast fiber (KF) composites were prepared with different amounts (0 to 40 wt%) of ethylene acrylate copolymer impact modifier (IM). With increasing IM content, the impact strength and elongation at break of the composites improved but an opposite trend was observed for the tensile strength and modulus. Addition of IM resulted in the formation of ductile or flexible interface between the PLA matrix and KF as confirmed by scanning electron microscopy examination on the composite fractured surfaces. Deformability of the PLA matrix was also improved. Mechanisms for the morphology-property relationships of the composites were discussed.