Effective recycling of end-of-life polyvinyl chloride foams in ethylene–propylene diene monomers rubber

Rigid cross-linked interpenetrated network polyvinyl chloride (PVC) foams are widely used as core materials in the composite industry. Nevertheless, no recycling methods exist today for these materials that are currently landfilled at the end of life (EoL). In this work, various amounts of EoL PVC cross-linked foams in the form of chips were mixed with ethylene–propylene diene monomer (EPDM) rubber and carbon black (CB) at 60°C for 15 min. The obtained rubber mixtures were vulcanized at 160°C for 20 min to create compacted square sheets of EPDM-CB-PVC composites using compression molding technique. Tensile tests revealed a progressive increase in modulus of EPDM-CB with increasing PVC content while a subsequent decrease of the elongation-at-break values of the composites was noticed. Scanning electron microscopy revealed a homogeneous dispersion of PVC particles with the EPDM-CB matrix. Improved interfacial adhesion of filler in the matrix was also observed at higher PVC content as well. Hardness tests revealed an increased Shore A values by 25% with added PVC waste in EPDM-CB. Concurrently, a steady increase in compression set was observed in the rubber composites with the added PVC filler. Additionally, due to added filler, thermal conductivity was decreased by 35% compared to pure EPDM-CB.