Abstract:

In order to study the influence of molecular structure and different processing parameters on the crystallization behavior of polyamide 56 fibers, the crystallization characteristics of different kinds of polyamides and bio-based polyamide 56 fibers by different processing ways were investigated by X ray diffraction.The crystallization behavior of polyamide 56 under different cooling rates were also analyzed by DSC testing experiments in this work. The results show that the crystallinity and the degree of orientation in crystalline region are the lowest compared with polyamide 6 and 66. The crystal cells of bio-based polyamide 56 fiber are not exactly equal in height and there may be some defects in crystalline region. Different processing ways of bio-based polyamide 56 fiber will result in different crystallization behaviors. The crystallization of bio-based polyamide 56 increases with the increase of the cooling rate and the crystallization rate reaches the maximum value when the temperature drops to about 210 °C. Furthermore, The faster the cooling rate is, the smaller the formation of the spherulite size is.

Key words: bio-based polyamide 56 , polyamide 6, polyamide 66, processing way, cooling rate, crystallization behavior