Compatibilization effect of POE-g-MAH on PA1010-PP blends obtained via dynamic packing injection molding

Various polyamide-polypropylene (PA1010-PP) blends were prepared by melt mixing using maleic anhydride-grafted ethylene-octene copolymer (POE-g-MAH) as a compatibilizer. In order to investigate the compatibilizing effect of POE-g-MAH on PA1010-PP blends obtained via dynamic packing injection molding (DPIM), morphologies, mechanical and crystallizing properties of the blends were characterized by means of scaning electron microscopy (SEM), mechanical testing and differential scaning calorimetry (DSC), respectively. It is found the tensile strength, tensile modulus and notched impact strength largely increase by applying shear stress during injection molding. SEM results show a remarkable decrease of domain size, more uniform dispersion and more fuzzy interface of the dynamic molded specimens, which indicates that shear stress can accelerate compatibilization. DSC results show that two crystalline peaks appear in dynamic samples when POE-g-MAH reaches 15%, the crystallization of PP at the lower temperature should be assigned to homogeneous nucleation, the other one is heterogeneous nucleation. The appearance of homogeneous nucleation demonstrates that the size of PP particles is very fine in the matrix. The enhancement of compatibilization effect of POE-g-MAH on PA1010-PP blends under shear stress could be due to the effect of shear-induced particular morphologies.