Crystallization behaviors and confined mechanisms of LiCl modified polyamide 6

In order to broaden the engineering application areas of polyamide 6 (PA6), LiCl/PA6 composites were prepared by melting extrusion firstly. Then, the effects of LiCl content on crystallization behaviors and mechanical properties of PA6 as well as the restricted mechanisms of crystallization were investigated by XRD, DSC, rheometer and electronic tensile testing machine et al. The results show that with LiCl content increasing, the temperature of nucleation, the growth temperature and melt temperature of spherulites of LiCl/PA6 composite systems all move toward low temperature direction; the density and rate of nucleation both decrease gradually, which leads to the decrease of crystallization ability, and the crystallinity decreases from the original 36.5% to 5.6%; the crystallinity of γ-crystal decreases gradually, while the crystallinity of α-crystal initially increases and then decreases, transformation occurs between γ-crystal and α-crystal. In addition, the tensile strength and impact strength of LiCl/PA6 composites both increase firstly and then decrease, when LiCl content is 6.0wt%, impact strength reaches the maximum 7.9 kJ/m², which is 1.44 times of the impact strength of pure PA6 (5.5 kJ/m²).