STUDIES ON DYNAMICALLY VULCANIZED POLYPROPYLENE (PP) BUTADIENE STYRENE BLOCK-COPOLYMER (SBS) BLENDS - CRYSTALLIZATION AND THERMAL-BEHAVIOR

Crystallization of polypropylene (PP) in unvulcanized blends of PP wit h the butadiene-styrene block copolymer (SBS) was studied through diff erential scanning calorimetry (DSC) and X-ray diffraction measurements in the composition range of 0-40 wt % SBS content. Analysis of the cr ystallization exotherms revealed variation in the crystallization beha vior, crystallinity, and crystalline morphology of the PP component in the blends at various levels of SBS concentration. The crystallinity determined by X-ray diffraction and DSC showed identical variations wi th the blend composition. The tensile and thermal properties of the bl ends were studied in the entire composition range. Correlations of the tensile properties with the crystallization parameters of the PP comp onent in the blends are also presented. (C) 1999 John Wiley & Sons, In c.