Sandwich Panels and Polymer Blends from Recycled Polyethylene Terephthalate (PET) and other Post-Consumer Plastics

The exponential increase in global plastic wastes dangerously impacts the environment and human health. In this study, Polyethylene Terephthalate (PET), High-density Polyethylene (HDPE), Polypropylene (PP), and Polymethyl methacrylate (PMMA) were recycled into sandwich panels and polymer blends. Recycled PET (rPET) fibers, with 25 and 50 fibers, were used as the middle layer for the sandwich panels. The face layers were made from the recycled HDPE (rHDPE), recycled PP (rPP), and recycled PMMA (rPMMA). The weak interaction between rPET fibers and the face panels resulted in low mechanical performance. The sandwich panel with rPMMA as the face layers and 25 rPET fibers as the core exhibited good overall mechanical performance. The stiffness of sandwich panels was improved. The polymer blends were prepared using rPET at 70 wt% and other plastic wastes at 30 wt%. The addition of a compatibilizer can enhance the mechanical properties of polymer blends. The rPET/ rPP blend and rPET/ rHDPE blend showed slightly higher mechanical performance compared to the rPET/ rPMMA blend. All polymer blends exhibited higher flexural strength, impact strength, and hardness compared to neat rPET.