T
he reinforcing effect of chopped rice husk (CRH) into polypropylene has been studied. Composites containing different amounts of CRH with 0 to 40 parts per hundred part of polymer (php) were prepared using a co-rotating twin screw extruder and characterized by mechanical properties and also water absorption. Inorder to increase the interphase adhesion, polypropylene grafted with maleic anhy-dride was added as a coupling agent to all the composites studied. It was found thatthe tensile and flexural modulus of the composites containing 40 php of CRHincreased approximately by 33% and 100%, respectively. The results also showed thatwhile flexural strength was moderately improved by increasing of CRH into the matrix,elongation-at-break and energy-at-break decreased dramatically. Areasonable adhe-sion between the main components was also observed by examining the scanningelectron micrographs. Water absorption experiments showed that although the diffu-sion coefficient increased with CRH loading, all the composites followed case I diffu-sion.