IMPROVING THE INTERFACE IN NATURAL FIBRES REINFORCED PLA BIOCOMPOSITES BY OPTIMIZED ORGANOSILANE TREATMENTS
Résumé
In this study, we investigated the effect of an organosilane treatment on the surface properties
of flax fibres and the resulting mechanical properties of flax fibres reinforced poly(lactic
acid) biocomposites. Optimizing the organosilane treatment conditions increases the
hydrophobicity of the fibres, and improves significantly the stiffness, the ultimate stress and
the impact strength of the biocomposites, while reducing largely the scattering of their
properties. Dynamic mechanical analysis reveals a decrease in damping of treated
biocomposites because of the formation of a thicker layer of immobilized macromolecular
chains resulting from strong interactions at the interface. Crack propagation is observed on
notched samples by in situ tensile tests in a scanning electron microscope. The treated
biocomposites show a cohesive failure at much higher loads which highlights the enhanced
load transfer from the PLA matrix to the flax fibres.