β-Crystal formation of isotactic polypropylene induced by N, N’-dicyclohexylsuccinamide

N, N’-dicyclohexyl succinamide (DCS) was found to be a new β-nucleating agent for isotactic polypropylene (iPP) by means of wide angle X-ray diffraction (WAXD) and polarized light microscopy (PLM) measurements for the first time. The maximum proportion of β-form within iPP specimen was 79.1% with addition of 0.05% DCS. With increasing crystallization time, the proportion of β-form changed slightly when the nucleated iPP specimens crystallized at 120°C and 130°C for more than 20 min; but at 140°C, the content of β-form markedly decreased because β-α solid to solid transformation occurred. The analysis of the cell parameters of DCS and β-form iPP showed good lattice matching relationship between them.