Melting and crystallization behaviors, morphology, and mechanical properties of b polypropylene/polypropylene graft maleic anhydride/calcium sulfate whisker composites
The melting and crystallization behaviors, morphology, and mechanical properties of polypropylene (PP)/surface treated calcium sulfate (CaSO4) whisker (T CSW) b PP/T CSW, and b PP/polypropylene graft maleic anhydride (PP g MAH)/T CSW composites had been investigated via differential scanning calorimetry (DSC) wide angle X ray diffraction (WAXD) polarized light microscopy (PLM) scanning electron microscopy (SEM) and mechanical tests. We found that T CSW was an a nucleating agent and increased the crystallization temperatures of PP, but PP g MAH and high loadings of T CSW had weakly negative effects on the crystallization rates of PP. The T CSW restrained the formation of b spherulites, and the spherulitic size decreased in the composites. PP g MAH improved the compatibility and adhesion between T CSW and the matrix. The notched impact strength was improved, and the tensile strength was enhanced at low levels of T CSW, while the flexural modulus was weakened for b PP/T CSW and b PP/PP g MAH/T CSW composites versus PP/T CSW composites. POLYM. COMPOS. 2015. (c) 2015 Society of Plastics Engineers