Valorization of Pyrolyzed Waste Polystyrene and Cashew Nut Shell Oil (CNSO) as a Sustainable Hybrid Binder for High-Performance Paint

Abstract

The coating industry's quest for sustainable alternatives has been sparked by the buildup of non-biodegradable expanded polystyrene (EPS) trash and the environmental harm caused by traditional petroleum-based binders. The purpose of the study was to assess how these two waste streams could work in concert to improve the final paint binder's physicochemical characteristics. Excellent performance characteristics were demonstrated by the optimized hybrid binder (PS/CNSO), which recorded a density of 1.280 g/cm³, a pH of 4.78, and a turbidity of 101.2 NTU. A refractive index of 1.556 and a melting point of 139°C were determined by thermal and optical analyses, respectively. Importantly, the binder showed good brushability with a viscosity of 16.2 mPa.s, and it showed no moisture uptake, indicating outstanding hydrophobic qualities and environmental endurance.These findings show that the combination of CNSO and PSPO improves flexibility and water resistance while successfully reducing the brittleness of recycled plastics. This study offers an economical and environmentally responsible method for producing high-quality paint by using waste materials that are produced locally, greatly lowering the environmental impact of plastic and agricultural waste. By using a batch pyrolysis process to transform solid EPS waste into a liquid intermediate and mixing it with locally sourced Cashew Nut Shell Oil (CNSO) in different concentrations, this study effectively illustrates a "waste-to-wealth" strategy