Effect of Surface Treatments on Zea mays Husk and the Behaviour of Husk/Low-Density Polyethylene Composites

(1) Background: The increasing generation of plastic and agricultural wastes is a critical environmental issue that requires urgent attention. Aiming to address this challenge, this study developed a sustainable waste-to-wealth system through the utilization of Zea mays husk as a reinforcing material in the production of green composites. (2) Methods: Delignification, de-hemicellulolysis, and bleaching were employed sequentially to improve the characteristics of the husk. Fourier-transform infrared spectroscopy and scanning electron microscopy confirmed the removal of lignin, hemicellulose, and impurities, and X-ray diffraction analysis determined the degree of crystallinity. Composites were made with treated and untreated husk and recycled low-density polyethylene (LDPE) at various husk-to-LDPE ratios. (3) Results: Mechanical characterization demonstrated that the treated husk composites exhibited superior tensile strength, flexural strength, and hardness compared to the untreated ones and pure LDPE. The treatment did not enhance the thermal stability of the composites, but it did lower their capacity for water absorption and improve their crystallinity. The economic assessment of the husk composite production indicated a total annualized cost of USD 0.9601 per kg, which is significantly lower than the estimated cost for LDPE (USD 1.2 to USD 1.4 per kg). Additionally, it has a much smaller carbon footprint compared to LDPE production. (4) Conclusions: The potential of utilizing treated Z. mays husk as a reinforcing agent in the development of sustainable and cost-effective green composites, improving their overall performance, was established. This approach offers a promising solution for the effective management of plastic and agricultural wastes, contributing to the transition towards a circular economy.