Unlocking superior properties in polypropylene/polyethylene terephthalate (PP/PET) blends using an ethylene-butylene-acrylate terpolymer reactive compatibilizer

The increasing global plastic production has created an urgent demand for energy-efficient processes to transform mixed plastic waste into value-added products via upcycling. Compatibilization of polypropylene (PP) and poly(ethylene terephthalate) (PET), two used semi-crystalline polymers in industry, is investigated in this study. We evaluate the effectiveness of an ethylene-butylene-acrylate terpolymer (PTW) at different contents in a 70/30 PP/PET blend, examining the resulting physico-chemical characteristics. Adding PTW as compatibilizer significantly reduces the droplet size in the PP/PET blend, improving rheological and mechanical properties. Remarkably, the blend containing 1.5 % PTW exhibits maximum enhancement in mechanical properties. To understand deeply the chemical compatibilization mechanism, Fourier transform infrared spectroscopy (FTIR-ATR), Atomic Force Microscopy combined with infrared spectroscopy (AFM-IR), and Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR) techniques were employed. The compatibilizer was located at the interphase, and the chemical reaction using AFM-IR and 1H NMR was tracked. These advanced techniques prove the chemical compatibilization mechanism in PP/PET blends with PTW. These findings contribute to understanding the compatibilization processes, offering valuable guidance for developing efficient upcycling processes for mixed plastic waste.