Investigation on β-polypropylene/PP-g-MAH/surface treated talc composites

beta-Polypropylene composites containing talc treated by titanate coupling agent (T-talc) and maleic anhydride grafted PP (PP-g-MAH) were prepared by melt compounding. The crystallization, morphology, and mechanical properties of the composites were investigated by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), polarized light microscopy (PLM), scanning electron microscopy (SEM), and mechanical tests. It is found that nucleating agent (NT-C) induces the formation of -phase but T-talc suppresses the formation of -modification. Both NT-C and T-talc greatly decrease the spherulitic size of PP. PP-g-MAH has a weak restraint on the formation of -form PP but it improves the compatibility between T-talc and PP matrix. Izod notched impact strength of -PP/T-talc composite is higher than that of PP/T-talc composite at each loading, indicating the toughening effect of -PP. Incorporation of PP-g-MAH into -PP/T-talc composite further increases the impact strength when T-talc concentration is below 2.5 wt %. The non-isothermal crystallization kinetics of -PP composites is well described by Jeziorny's and Mo's methods, respectively. The activation energies (E) of non-isothermal crystallization were calculated by Kissinger method. It is found that NT-C and T-talc accelerate the crystallization rate of PP but PP-g-MAH has a slightly negative influence on the crystallization rate of -PP. (c) 2013 Wiley Periodicals, Inc.