Effect of silane treatment loading on the flexural properties of PLA/flax unidirectional composites

Matrix/fiber interfacial bonding, is one of the most significant issues that needed to be addressed, for the wider acceptance of natural fiber reinforced composites to outdoor applications. The hydrophilic nature of the specific fibers is a major obstacle for the bonding with the hydrophobic polymer matrices, thus the formation of poor interface between the two components is inevitable. In this study, unidirectional flax fiber reinforced Polylactic Acid (PLA) composites (Flax/PLA)were fabricated through “film stacking method”, resulting to panel samples. Flax fibers were treated with amino-silane coupling agent, at different silane content values, in order to optimize the composite properties regarding this parameter. The effect of the amount of treatment onPLA/Flax composites has been studied in terms of their flexural response, both static and creep, in order to evaluate their long-term performance as a function of the silane treatment. Results about the effectiveness of silane-treated flax fibers on the mechanical performance of the bio-composite under investigation have been obtained. It has been found that silane loading over a specific number, results to deterioration of the composite's properties.