Rheologically determined phase behavior and miscibility of reactively compatibilized poly(ethylene terephthalate)/polypropylene blends

Rheology, phase behavior and morphology of poly(ethylene terephthalate)/polypropylene (PET/PP) blends compatibilized with maleic-anhydrate-grafted-PP (PP-g-MA) and n-butyl-acrylate-glycidyl-methacrylate-ethylene (EBGMA) were studied. According to infrared spectroscopy results, whereas PP-g-MA was merely capable of reacting with hydroxyl groups of PET, epoxy groups of EBGMA could react with both the hydroxyl and carboxyl end groups of PET. The enhanced compatibilizing effect of EBGMA on PET/PP systems over PP-g-MA was also revealed by scanning electron microscopy and mechanical experiments. From frequency and temperature sweep rheological experiments, the dynamic characteristics of the compatibilized blends found to be improved in comparison with those of the uncompatibilized system. Such enhancement was interpreted as a result of the higher miscibility of the compatibilized blends which was further supported by Cole–Cole plot analyses.