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以枝化剂为超支化聚酰胺6(PA6)的引发剂,配以含有端羧基官能团的有机改性剂改性的有机蒙脱土(O-MMT),经原位开环接枝聚合制备了O-MMT/超支化PA6复合材料。通过FTIR和TEM表征了超支化PA6与O-MMT的接枝情况以及O-MMT在基体中的分散形态。研究了O-MMT对超支化PA6结晶性能、熔体流动性能和力学性能的影响。结果表明:O-MMT呈剥离态和插层态分散于超支化PA6基体中,且与PA6分子链段产生化学键合,形成网络交联结构。网络交联结构使O-MMT/超支化PA6复合材料与超支化PA6相比熔体流动指数急剧下降。另外,O-MMT使超支化PA6的α晶型消失,且使仅有γ晶型的超支化PA6的结晶度降低。但随O-MMT含量增加,O-MMT/超支化PA6复合材料的强度逐步提高,拉伸强度从38.4MPa提高至60.8 MPa。复合材料的韧性也得到大幅度提高,断裂伸长率从2.1%提高至70.1%,无缺口冲击强度从20.3kJ/m2急剧提高至291.8kJ/m2。
The dendrimer was used as initiator of hyperbranched polyamide 6 (PA6) and organic montmorillonite (O-MMT) modified by organic modifier with terminal carboxyl functional group, which was prepared by in-situ open-loop graft polymerization O-MMT / hyperbranched PA6 composites. The grafting of hyperbranched PA6 with O-MMT and the dispersion of O-MMT in the matrix were characterized by FTIR and TEM. The effects of O-MMT on the crystallization, melt flow and mechanical properties of hyperbranched PA6 were studied. The results show that the O-MMT is in a state of exfoliated and intercalated dispersed in the hyperbranched PA6 matrix and chemically bonded with the molecular chain of PA6 to form a network cross-linked structure. The network cross-linked structure resulted in a drastic drop in the melt flow index of the O-MMT / hyperbranched PA6 composite compared to the hyperbranched PA6. In addition, O-MMT disappears α crystal form of hyperbranched PA 6, and crystallinity of hyperbranched PA 6 having only γ crystal form decreases. However, with the increase of O-MMT content, the strength of O-MMT / hyperbranched PA6 composites gradually increased, tensile strength increased from 38.4MPa to 60.8MPa. The toughness of the composites has also been greatly improved, the elongation at break increased from 2.1% to 70.1%, and the unnotched impact strength increased sharply from 20.3 kJ / m2 to 291.8 kJ / m2.