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

N, N'-dicyclohexyl succinamide (DCS) was found to be a new beta-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 beta-form within iPP specimen was 79.1% with addition of 0.05% DCS. With increasing crystallization time, the proportion of beta-form changed slightly when the nucleated iPP specimens crystallized at 120A degrees C and 130A degrees C for more than 20 min; but at 140A degrees C, the content of beta-form markedly decreased because beta-alpha solid to solid transformation occurred. The analysis of the cell parameters of DCS and beta-form iPP showed good lattice matching relationship between them.