Micromechanical Properties of Recycled Waste PVC–Graphene Oxide Composite Sheet for High-Performance Construction Applications

Poly(vinyl chloride) (PVC) waste poses serious environmental challenges, making it necessary to explore sustainable recycling approaches for value-added applications. In this work, recycled poly(vinyl chloride) (rPVC) composite sheets reinforced with graphene oxide (GO) were developed for potential use in construction through hydraulic compression molding. Postconsumer and industrial rPVC waste was first cleaned, shredded, ground, and blended with GO (0–5.5 wt%), followed by molding at 170°C–180°C under 10 MPa. Mechanical testing in accordance with ASTM D638, D790, and D695 standards showed that the incorporation of GO enhanced the properties of the composites, with the optimum performance at 2.5 wt%. At this level, tensile, flexural, and compressive strengths reached 48.2, 80.2, and 62 MPa, respectively, after which further additions led to strength reduction due to filler agglomeration. Microstructural analysis revealed uniform GO dispersion, strong interfacial bonding with PVC, reduced voids, and a more compact morphology, indicating effective reinforcement at optimal loading. Overall, the study highlights that rPVC/GO composites offer a sustainable route to produce mechanically robust and thermally stable materials suitable for structural and infrastructural applications, contributing to the advancement of the circular economy.