Study on interfacial properties of unidirectional flax/vinyl ester composites: Resin manipulation on vinyl ester system

Flax fibers are widely used as reinforcements in bio-based polymer matrix composites. This study investigated the hydrophilic nature and surface purity of flax fiber that affects fiber/matrix adhesion in combination with hydrophobic structural polymers via matrix modification and the utilization of fiber treatment, specifically in a flax/vinyl ester (VE) composite. A new method to manipulate the vinyl ester system with acrylic resin (AR) was developed to produce flax reinforced. On the other hand, different types of chemical and physical treatments were applied on the flax fiber. FTIR was applied to evaluate the effects of surface treatments. Dynamic mechanical analysis (DMA) was used to analyze the unmodified and modified VE resin system. The surface of untreated and treated flax fibers and their composites were analyzed by scanning electronic microscopy (SEM). Sodium ethoxide-treated flax/VE with 1% (wt) AR caused the best mechanical performance among all the flax/VE composites evaluated.