BIOPLASTICS DERIVED FROM RICE HUSK AND RICE STRAW

Abstract

Rice husk and rice straw are among the largest lignocellulosic residues generated by global agriculture, yet a substantial share of this biomass is still burned or landfilled rather than valorized. Over the past decade, researchers have explored these residues as feedstocks for bioplastics intended to displace petroleum-based polymers in packaging, disposable products, and even building materials. This review synthesizes findings from six primary studies that convert rice husk or rice straw into bioplastic materials through distinct routes: fiber reinforcement of commercial bioplastics, starch-flour film casting, regenerated cellulose film casting, starch-filler composites, chemical esterification of cellulose, and simultaneous cellulose-silica co-extraction. Across these studies, mechanical strength, water sensitivity, and biodegradation rate consistently trade off against one another, and the natural silica present in both residues repeatedly emerges as a functional component rather than a mere impurity, contributing to flame retardancy, reinforcement, and barrier performance. The review compares the processing conditions and resulting properties of each approach and discusses the remaining obstacles to scaling rice-residue bioplastics toward commercial packaging and disposable-product applications.