Crystallization and melt behavior of Mg(OH)2/PP composites modified by functionalized polypropylene

The crystallization and melting behavior of Mg(OH)(2)/PP composites modified by the addition of functionalized polypropylene (FPP) or acrylic acid (AA) and the formation of in situ FPP were investigated by DSC. The results indicated that addition of FPP increased the crystallization temperatures of PP because of the nucleation effect of FPP. The formation of in situ FPP resulted in a reduced crystallization rate, melting point, and degree of crystallization attributed to the decreased regularity of the PP chain. For Mg(OH)(2)/PP composites, the addition of Mg(OH)(2) increased the crystallization temperatures of PP resulting from a heterogeneous nucleation effect of Mg(OH)(2). The addition of FPP into Mg(OH)(2)/PP composites further enhanced the crystallization temperatures of PP. It is suggested that there is an activation of FPP to the heterogeneous nucleation effect on the Mg(OH)(2) surface. The addition of AA also increased the crystallization temperatures of PP in Mg(OH)(2)/PP composites, although the crystallization temperature of PP was not influenced by the AA content, which is explained by the heterogeneous nucleation effect of the Mg(OH)(2) surface activated by FPP and AA. A synergistic effect on the crystallization of PP in Mg(OH)(2)/PP composites further increased the crystallization temperatures of PP. However, The crystallization temperatures of Mg(OH)(2)/PP composites modified by in situ FPP were lower than those of Mg(OH)(2)/PP composites modified by addition of either FPP or AA. (C) 2004 Wiley Periodicals, Inc.