Effect of Fiber Treatment Condition and Coupling Agent on the Mechanical and Thermal Properties in Highly Filled Composites of Sugarcane Bagasse Fiber/PP

This paper reports on a study of highly filled composites of polypropylene (PP) and 75% by weight sugarcane bagasse fiber with and without alkali treatment and with and without coupling agent (SEBS-g-MA). Composites were prepared using a Rheomix600 mixer connected to a HAAKE torque rheometer. The thermal and mechanical behavior of these composites were investigated by thermogravimetry (TGA), differential Scanning Calorimetry (DSC), flexural tests, impact tests and scanning electron microscopy. Scanning electron microscopy (SEM) images taken from sugarcane bagasse fibers showed enhancements in the fiber's surface topography after the surface treatment process. The FTIR, TGA and SEM results for the fibers showed that the alkali treatment modified the fiber surface as well as the chemical composition. The impact test results showed a good potential of SEBS-g-MA as coupling agent and impact modifier in highly filled composites, increasing by more than 100% the impact strength of the composite as compared to those without the coupling agent. Scanning electron microscopy showed that addition of coupling agent improved the interfacial adhesion between the fibers and polypropylene.