Production of Natural Straw-Derived Sustainable Polymer Composites for a Circular Agro-Economy

n this study, attempts were made for the first time to explore theunexploited wheat straw particulates (WSP) as a reinforcement filler withconcentrations up to 100% in a thermoplastic polypropylene (PP) matrix to producea new type of wood plastic composites. The WSP-PP composites were developed bymelt blending using the injection molding technique and were investigated for theirmechanical, structural, and thermal properties. The present study showed low-densitycomposites with densities varying from 0.84−1.04 gm/cc. Compared to virginpolypropylene, WSP-PP composites showed enhanced impact strength, improvedflexural strength and moduli, and lower water absorption. With increasing WSPconcentration, the mechanical strength increases, and at 20−30% filler concentration,the composite showed a maximum tensile strength of 27.21 ± 0.67 MPa and flexuralstrength of 44.48 ± 0.48 MPa. The maximum impact strength of WSP-PP composites(2.04 ± 0.11 kJ/m2) was recorded at 40% filler concentration along with lower waterabsorption (1.67%). The addition of WSP was found to decrease the thermal conductivity of the WSP-PP composites. The findingsof this study confirmed the scope of wheat straw as a potential cellulosic reinforcing filler for manufacturing a new class of greencomposites of high-performance characteristics which could be explored and beneficial for electrical applications, civil infrastructure,automotive parts, etc. Further, the utilization of this inexpensive raw material for the development of composites leads to a reductionin the practice of open straw burning in fields, thereby causing a decrease in CGH emissions. Thus, the realization of this innovativework will contribute to achieving the United Nations’ sustainable development goals with a sustainable approach toward building acircular economy.v