Real-time investigation of crystallization in nylon 6-clay nano-composite probed by infrared spectroscopy

Via time-resolved FTIR, we examined the real-time investigation of the structural change in molecular chain of nylon 6 during crystallization of neat nylon 6 and the corresponding nano-composite (N6C3.7) having fully exfoliated structure. The neat nylon 6 predominantly formed alpha-phase in the crystallization temperature (T-c) range of 155-195 degrees C. For N6C3.7 crystallization at low T-c range of 150-168 degrees C, where the network structure formed by the dispersed clay particles still affected chain folding of nylon 6, the formation of the gamma-phase was dominant. The crystallization took place so rapidly (less than 1 s) without induction time of crystallization. At high T-c range (=177-191 degrees C), the stable growth of the alpha-phase crystal coexisting with gamma-phase occurred in N6C3.7 crystallization. The growth mechanism in the subsequent crystallization processes (amides III alpha and III gamma) was virtually the same in both N6C3.7 and neat nylon 6. (C) 2010 Elsevier Ltd. All rights reserved.