Influence of epoxidized ethylene propylene diene rubber on nonisothermal crystallization kinetics and mechanical properties of poly(butylene terephthalate)/polypropylene blend

Abstract

Abstract The epoxidized ethylene propylene diene rubber (eEPDM) was successfully prepared by the epoxidation of ethylene propylene diene rubber (EPDM) using t-butyl hydroperoxide as the oxidant in association with molybdenum oxide as the catalyst and characterized by Fourier-transform infrared (FTIR) spectrometer and 1H-nuclear magnetic resonance analyses. Then the poly(butylene terephthalate) (PBT)/eEPDM/polypropylene (PP) blends with different eEPDM contents were prepared using a twin-screw extruder, and the effect of eEPDM on nonisothermal crystallization kinetics of PBT/PP blend was investigated by differential scanning calorimetry. Meanwhile, morphological features of samples were observed using scanning electron microscopy. Also, the mechanical properties of samples were evaluated. Analyses of the crystallization data by various macro-kinetic models like Jeziorny modified Avrami and Liu-Mo model demonstrated that PP as diluents accelerated the crystallization of PBT in PBT/PP. Moreover, the addition of eEPDM into PBT/PP further facilitated the crystallization of PBT in PBT/eEPDM/PP. The eEPDM was an effective crystallization promoter for PBT/PP blend. And the presence of eEPDM promoted the uniform dispersion of PP in PBT matrix. When the content of eEPDM was 5 phr, the PBT/eEPDM/PP exhibited the highest notched impact strength and Young’s modulus among all the specimens.