Effect of fiber chemical treatment of nonwoven coconut fiber/epoxy composites adhesion obtained by RTM process

In this work untreated and alkali treated nonwoven coconut fiber mats/epoxy resin composites were manufactured using the resin transfer molding process. The alkaline solution removes some impurities present on fibers superficial layers and the effect regarding fiber/matrix adhesion were investigated by thermogravimetric analysis, dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), ultrasonic C‐scan, and quasi‐static flexural test. Results show a removing of some amorphous fibers constituents, mainly waxes, extractives, and hemicellulose, revealing the fiber roughness surface but no initial degradation temperature changing. Regarding the composites, a similar interfacial adhesion was observed in both one through the results of SEM, DMA and quasi‐static flexural tests. The conclusion is that chemical treatment conditions applied on the fiber surface was been suitable to improve fiber roughness but did not the adhesion between coconut fibers mat and epoxy resin. POLYM. COMPOS., 38:2518–2527, 2017. © 2015 Society of Plastics Engineers