Effect of Rice Husks as Filler in Polymer Matrix Composites

In this study, rice husk-filled polyester composites were produced with rice husks (RH) as the filler and unsaturated polyester resin (UPR) as the matrix. Several percentages of filler loadings were used (10, 15, 20 and 25 wt %) in order to gain insights into the effect of filler content on the mechanical properties and water intake of the composites. The tensile strength of the RH-filled UPR composites was found to decrease as the filler loading increased; however, as it reached 25 wt %, the strength showed a moderate increase. The Young’s modulus showed a remarkable increase for 15 wt % of RH but decreased as the RH percentage increased further to 25 wt %. A water absorption test was conducted and the results showed that the composites absorb more water as the percentage weight of RH increased, which is attributed to the ability of the RH filler to absorb water.