Flexible Thermoplastic Composite of Polyvinyl Butyral (PVB) and Polyvinyl Chloride (PVC) with Rigid Polyurethane Foam (PUr)

Rigid polyurethane foam (PUr) is a common residue from the footwear industry that seeks a sustainable disposal alternative. A flexible composite incorporating PUr that could be used in this same industry is an exciting solution. Poly (vinyl chloride) (PVC) and polyvinyl butyral (PVB) were tested as possible matrixes for flexible composites containing 20%, 35%, and 50% of PUr produced by two different processes, extrusion and injection molding. PVB/PUr and PVC/PUr were compared considering the morphology observed with scanning electron microscopy (SEM), density, degradation during processing, and dynamical mechanical properties. PVC was severely degraded when processed with PUr and showed a low adhesion to PUr particles resulting in decreased storage modules and increased glass transition temperature. PVB is a better matrix for PUr flexible composites since it showed no sign of degradation and formed a stronger interface with PUr particles resulting in PVB/PUr composites with higher storage modulus.