Crystallization of filled nylon 6 III. Non-isothermal crystallization

Summary DSC data on crystallization kinetics from the melt at different cooling rates of nylon 6 containing various amonts of untreated and surface-treated fillers, were analyzed in terms of a modified Kolmogorov-Avrami equation. It was established that mechanism of crystallinity development in molten nylon 6 does not change appreciably in presence of aminosilane-treated glass beads and small amounts of untreated glass beads, whereas time exponentn was found to decrease with increasing filler content in samples containing untreated glass beads and Aerosil. On the other hand, dependence of temperature of the onset of crystal nucleation on cooling rate obeyedm = 2 law for pure nylon 6 and samples containing surface-treated filler, whilem = 4 law seemed to hold for samples containing large amounts of untreated fillers at low cooling rates (m is the exponent at degree of supercooling). It was concluded that although isothermal conditions of crystallization should be preferred for further quantitative investigations of polymer-filler interactions in highly filled polymer melts, the above results qualitatively are consistent with trends discovered in isothermal crystallization experiments.