Formulation of binder-extender composite resin from recycled plastic wastes for the production of emulsion paint

Plastic waste valorization is a critical aspect of waste management. In this study, recycled polyethylene (rPE) was prepared by suspending microparticles of low-density polyethylene (LDPE) waste in LDPE pyrolysis oil. The rPE was then blended with waste polystyrene pyrolysis oil (PPO) to form a drying plastic-based composite resin (rPEPPO). As the rPE content increased, rPEPPO exhibited significant decrease in drying time (90–50 min) and elongation-at-break (800–5%). Its physicochemical properties also varied, including viscosity (2.75–3.98 P), density (0.73–0.8 g/cm³), melting point (119–157°C), and moisture uptake (0–0.036%). FTIR, XRD, SEM, AFM, and TGA analyses of the rPEPPO blended in a 1:1 ratio revealed distinct structural features and interactions, suggesting copolymerization and/or cross-linking that enhance curing, drying, and structural reinforcement. Incorporating rPEPPO as a binder-extender component in water-based paint formulations delivered promising performance, indicating the potential of the composite resin for use in domestic and industrial coatings. This approach supports circular economy goals by introducing a novel technique for transforming plastic waste into functional materials.