含液晶结构单元改性剂改性环氧树脂性能的研究--柔性链分子量的影响

合成了一种既含环氧丙烷聚醚（ＰＰＧ）柔性间隔基、又含刚性液晶结构单元的活性增韧剂（ＬＣＥＵＰＰＧ），用其改性环氧树脂Ｅ－５１／双氰双胺（Ｅ－５１／ｄｉｃｙ）固化体系．对改性固化体系的动态粘弹行为、冲击性能与改性剂分子量大小之间的关系进行了探讨．结果表明：冲击强度虽然在一定程度上依赖于改性剂的分子量大小，但含不同柔性链分子量的ＬＣＥＵＰＰＧ均可使固化体系的冲击强度提高３～７倍．改性体系的模量较未增韧体系的模量基本不降低或略有升高，玻璃化转变温度（Ｔｇ）随柔性链分子量的增大而略有提高．

STUDIES ON PROPERTIES OF EPOXY RESIN MODIFIED BY A MODIFIER CONTAINING LIQUID CRYSTALLINE UNIT --INELUENCE OF THE MOLECULAR WEIGHT OF THE FLEXIBLE CHAINS

A series of reactive toughening accelerators (LCEU PPG ) containing both the flexible chain and rigid chain liquid crystal unit that were synthesized to toughen the epoxy resin E 51 dicyandiamne/(dicy/E 51) curing system. Influence of molecualr weight of LCEU PPG on viscoelastic properties, impact strength for the modified systems were investigated. Compared with the unmodified system, the results showed that although impact strength of the modified samples to some extend depended on the molecular weight of LCEU PPG , it was improved for 3-7 times for all the modified curing system. Modulus of the modified system were equal to or highter than that of the unmodified under optimized condition. Glass transition temperature of the modified curing system was slightly increased with the increasement of the molecular weight of LCEU PPG .