A Review: Chemical Treatments of Rice Husk for Polymer Composites

Rice husk is one of the agricultural by-products produces worldwide. During the recent decade, much attention has been focused on rice husk utilization for composite materials. Apart from the rice industry's huge amount of rice husk, it has a dominant agricultural waste position due to its great properties. The treatments or modifications of fiber surface properties typically increase the adhesion properties of fibers and polymers yet affect the polymer composite's physical and mechanical properties. Prior studies revealed that chemical treatments consider as one of the most used methods for the surface treatments of agricultural fibers. This paper provides an overview of the rice husk as a reinforcing material in polymer composite. Various types of chemical treatments such as alkali, benzylation, anhydride, silane, and acetylation applied on rice husk polymer composite and their effect on physical and mechanical properties were investigated based on previous literature. Rice husk polymer composites with different chemical treatments and polymers were compiled, and their basic properties were reported. Therefore, this paper will benefit future works on rice husk chemical treatments in a composite application.