端活性聚丙二醇对环氧树脂的增韧改性

以端羟基聚丙二醇为基础合成了端羧基和端环氧基聚丙二醇，对不同端基聚丙二醇改性环氧树脂体系进行了DSC、DMA、冲击性能和冲断面SEM研究。随聚丙二醇端活性基与环氧树脂反应性的增强，固化体系更倾向于形成均相结构，环氧树脂固化物玻璃化温度降低更多。端羟基和端环氧聚丙二醇都能明显提高环氧树脂的冲击强度。综合分析测试结果表明聚丙二醇是通过增塑方式对环氧树脂进行增韧，而端环氧基聚丙二醇是通过提高交联网络柔性的方式对环氧树脂进行增韧。

Epoxy Resin Modified with Different End Group Polypropylene Glycol

Carboxyl-terminated polypropylene glycol (CTPPG) and epoxy-terminated polypropylene glycol(ETPPG) were synthesized from polypropylene glycol(PPG), the differential scanning calorimetry, dynamic mechanical thermal analysis, impact strength and impact fracture surface of the three different end group polypropylene glycol modified epoxy resin were investigated. The results showed that with the reactivity between the end group of polypropylene glycol and epoxy resin increase, the cured epoxy resin tended to form homogeneous structure, and the Tg depressed. Both of PPG and ETPPG can obviously increase the impact strength. Test results show that polypropylene glycol toughening epoxy resin is by way of plasticization, and epoxy-terminated polypropylene glycol toughening epoxy resin is by way of increasing the flexibility of the crosslinked network.