A review of composite materials based on rice straw and future trends for sustainable composites

Rice straw is an agricultural waste, disposal of which through open burning is an emerging challenge for the ecology, especially in under developed countries. Green composites manufactured using rice straw as reinforcement material provides a more avant-grade technique that not only nurtures environmental stewardship by reducing waste and carbon footprint but also fosters prosperity through innovative economic opportunities for rice cultivators. While earlier published reviews are focussed on rice husk based composites and their properties, this review attempts to critically examine the effect of fiber content, fiber size, fiber surface modification, compatibilizer addition, micro and nanofillers, hybridization, etc., on mechanical, thermal, morphological properties, etc. of rice straw based composite materials. Review has been specifically categorised according to the type of matrix materials which include conventional polymers, bio degradable polymers, recycled polymers. Review also dwells upon various applications of rice straw based composites as that is essential for sustainable upcycling of agricultural wastes like rice straw. Novel methods like manufacturing rice straw based composites using 3D printing are also compiled in the review along with future potential of rice straw composites in the sustainable filler-based biocomposites manufacturing sector.