有机蒙脱土改性超支化聚酰胺6的制备与表征

Preparation and characterization of organic montmorillonite modified hyperbranched polyamide 6

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。

With branched agent as the initiator of hyperbranched polyamide 6（PA6）,with organic modifier modified organic montmorillonite（O-MMT）which has the terminal carboxyl group,O-MMT/hyperbranched PA6 composites were prepared via in situ ring-opening graft polymerization.The grafting condition of hyperbranched PA6 and O-MMT,dispersing morphology of O-MMT in matrix were characterized by FTIR and TEM,and the effects of O-MMT on crystallization properties,melt flow properties and mechanical properties of hyperbranched PA6 were studied.Results show that O-MMT is exfoliated and intercalated dispersing in hyperbranched PA6 matrix,and chemically bonds with PA6 molecular chains to form crosslinked network structure,which makes the melt flow index of O-MMT/hyperbranched PA6 composites decrease sharply compared with hyperbranched PA6.In addition,O-MMT can make theα-crystal of hyperbranched PA6 disappear,and make crystallization degree of hyperbranched PA6 with onlyγ-crystal decrease.However,with the increase of O-MMT content,the strength of O-MMT/hyperbranched PA6 composites increase gradually,the tensile strength increase from 38.4MPa to 60.8MPa,the toughness of composites also has been greatly improved,the elongation at break increases from 2.1%to 70.1%,the unnotched impact strength increases from 20.3kJ/m2 increase to 291.8kJ/m2 sharply.