IMPROVING THE INTERFACE IN NATURAL FIBRES REINFORCED PLA BIOCOMPOSITES BY OPTIMIZED ORGANOSILANE TREATMENTS

In this study, we investigated the effect of an org anosilane treatment on the surface properties of flax fibres and the resulting mechanical propert ies of flax fibres reinforced poly(lactic acid) biocomposites. Optimizing the organosilane tr a ment conditions increases the hydrophobicity of the fibres, and improves signific antly the stiffness, the ultimate stress and the impact strength of the biocomposites, while red ucing largely the scattering of their properties. Dynamic mechanical analysis reveals a d ecrease in damping of treated biocomposites because of the formation of a thicker layer of immobilized macromolecular chains resulting from strong interactions at the in terface. Crack propagation is observed on notched samples by in situ tensile tests in a scann ing electron microscope. The treated biocomposites show a cohesive failure at much highe r loads which highlights the enhanced load transfer from the PLA matrix to the flax fibre s.