Effect of Bleaching Treatment on the Mechanical and Thermal Behavior of Flax Fibers Reinforced Poly-(Lactic Acid) (PLA) and Poly-(Butylene Succinate) (PBS) Biocomposites

Composites reinforced with plant fibers are widely used in the automotive and construction sectors. The vast majority is composed of petroleum-based, non-compostable polyolefins, which are no longer a viable solution in an environmental context where the end-of-life management of industrial products is becoming a major societal issue. Here, fully green composites are produced by reinforcing a blend of bio-based and biodegradable matrices, poly-(butylene-succinate) (PBS) and poly-(lactide) (PLA) with flax fiber. In this work, in order to improve the mechanical properties of 80PLA/20PBS formulation-based composite, flax fibers undergo bleaching treatment. The mixing and the injection shaping processes were used to prepare the composite samples. The composites were characterized to investigate the effect of the bleaching treatment in their thermal and mechanical resistance. The control of the adhesion between the matrix and the flax fibers reinforcement and final morphology is studied by Scanning Electron Microscopy (SEM). The results show that the chemical bleaching treatment increases the stiffness, the strength but decreases the strain of flax/ 80PLA-20PBS composite. That means an improvement of the adhesion between the 80PLA/20 PBS matrix and flax fibers. Also, the best performances are achieved with bleaching treatment.