Development and Characterization of Polymeric Composites Based on Poly (Lactic Acid) and Natural Fibers

This work evaluates the behavior of composites containing a biopolymer derived from sustainable agriculture industries. The biopolymer selected, poly(lactic acid) - PLA -, in combination with a thermoplastic polymer (polyurethane) - TPU - was mixed with natural fibers, wood and coconut. In a first step, formulations containing 10,20 and 30% by weight of fiber in relation to the blend of PLA-TPU (in the ratio 70/30 wt%) were prepared. In the second step, the same set of formulations was maintained but with addition of 5 wt% of the coupling agent maleic anhydride. These composites were characterized by means of physical-mechanical, thermal and microscopic techniques. The results indicated a low interfacial bonding between the polymeric blend and the vegetal fibers. It is important to emphasize the poor performance of the coupling agent, because the formulations containing maleic anhydride did not show any improvement in their properties in comparison to the standard material. Therefore, the biocomposites studied in this paper can be used when high-performance materials are not required, as in home decoration articles, making it feasible to use vegetal fibers in order to reduce the cost of the final composite.