Reinforcement of recycled PET for mechanical properties of isotactic polypropylene

For high-value use of recycled polyethylene terephthalate (r-PET) resource and simultaneous development of high performance isotactic polypropylene (PP) materials, the blends of r-PET with PP and its compatibilized versions were prepared. PP-g-MA, POE-g-MA and EVA-g-MA with same functional group, as well as their mixtures, were used as compatibilizer. The crystallization behavior, mechanical properties and microphotographs of r-PET/compatibilizer, r-PET/PP bleds and its compatibilized versions were characterized. The results indicated that addition of compatibilizer decreased the tensile and flexural strength of r-PET and slightly improve its impact strength. The introduction of r-PET to PP matrix increased the tensile and flexural strength of PP. The tensile and flexural strength of compatibilized r-PET/PP are dependent on the kinds of compatibilizers. Addition of PP-g-MA improved the tensile and flexural strength of r-PET/PP blends and introduction of POE-g-MA or EVA-g-MA increased the impact strength of r-PET/PP blends. Effect of compatibilizer and its mixtures and r-PET content on the mechanical properties of compatibilized r-PET/PP blends is discussed. The r-PET/PP blends with high strength and toughness can be obtained by compatibilization of the mixtures of PP-g-MA and POE-g-MA (or EVA-g-MA). This investigation provides an effective method to use the r-PET to prepare high performance PP blends with low cost and high-value.