Mechanical and Morphological Properties of Wood Plastic Biocomposites Prepared from Toughened Poly(lactic acid) and Rubber Wood Sawdust (Hevea brasiliensis)

Abstract

The present research aims to utilize the acrylic Core-Shell Rubber (CSR) particles to reduce the brittleness in Wood Plastic Composites (WPC) prepared from poly(lactic acid) (PLA) and rubber wood sawdust (Hevea brasiliensis). Experimental works consisted of two major parts. The first part concentrated on toughening PLA by using CSR particles. Mechanical tests revealed that PLA had become tougher with a more than five times increment in the impact strength when the CSR was added at only 5 wt%. The modified PLA was less stiff with the significant reductions of both elastic and flexural moduli and strengths. The second part focused on producing WPC from the toughened PLA and rubber wood sawdust. The tensile moduli and the strengths of the PLA composites increased with rubber wood content. The composites turned out to be more brittle with reductions of both the impact strength and the tensile elongation at break at all the sawdust contents. Toughening PLA/wood flour with 5 wt% CSR improved both the impact strength and the tensile elongation at break. The toughness enhancement was also depicted by the plastic deformation observed on the surfaces of fractured PLA/CSR/wood sawdust composites.