LiCl改性尼龙6的结晶行为及受限机制
Crystallization behaviors and confined mechanisms of LiCl modified polyamide 6

为了扩宽尼龙6(PA6)的工程应用领域,首先,通过熔融挤出制备了LiCl/PA6复合材料;然后,利用XRD、DSC、流变仪及电子拉伸试验机等研究了LiCl含量对PA6结晶行为和力学性能的影响及结晶的受限机制。结果表明:随LiCl含量的增加, LiCl/PA6复合体系的成核温度、晶体生长温度及熔融温度均向低温方向移动;成核密度和速率均逐渐减小,导致结晶能力下降,结晶度由原来的36.5%降低为5.6%;γ晶结晶度逐渐降低,而α晶结晶度先增大后减小, γ晶与α晶发生转变。此外, LiCl/PA6复合材料的拉伸强度和冲击强度均先增大后减小;当LiCl含量为6.0wt%时,冲击强度达到最大值7.9 kJ/m2,是纯PA6的冲击强度(5.5 J/m2)的1.44倍。 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). 贵州省教育厅自然科学研究项目(黔教合KY字[2013]158);贵州省教育厅研究生卓越人才计划(黔教研ZYRC字[2013]006号)