热塑性塑料对环氧树脂热膨胀系数的影响研究

Effect of thermoplastic on the coefficient of thermal expansion of epoxy resin

环氧树脂基体的热膨胀系数(CTE)对碳纤维增强环氧树脂层状材料的性能影响巨大,如何降低环氧树脂基体的CTE是提高碳纤维增强环氧树脂复合材料低温使用性能的关键。本研究采用聚对苯二甲酸丁二醇酯(PBT)、聚碳酸酯(PC)和聚醚酰亚胺(PEI)3种热塑性塑料改性环氧树脂,研究了这3种热塑性塑料对环氧树脂基体CTE的影响。结果表明:这3种热塑性塑料分子链中的羰基在环氧树脂固化过程中可与环氧分子侧链上的羟基形成氢键作用,从而加强了热塑性塑料与环氧树脂的界面作用;采用这3种热塑性塑料改性环氧树脂均可提高环氧树脂基体的玻璃化转变温度;相对于纯环氧树脂,PBT、PEI和PC改性的环氧树脂在玻璃化转变温度下的CTE分别降低了14.99%、17.44%和23.96%,但在玻璃化转变温度上的CTE均高于纯环氧树脂。

Coefficient of thermal expansion（CTE） of epoxy resin has a big influence on the property of carbon fiber reinforced epoxy laminate and how to decrease the CTE value of epoxy matrix is the key to improve the property of carbon fiber reinforced epoxy laminate at cryogenic temperature.Three kinds of thermoplastic were applied to modified epoxy resin and the CTE value of the resin was studied.The results showed that hydrogen bond was formed between C=O group of three kinds of thermoplastic and-OH of DGEBA epoxy resin during the course of curing,which strengthen the interfacial bonding between thermoplastic and epoxy matrix.Glass transition temperatures（Tgs） of three kinds of thermoplastic modified epoxy resin were all improved.In comparison to neat epoxy,the CTE values of PBT,PEI and PC modified epoxy resin below the Tg range were decreased 14.99%,17.44% and 23.96%,respectively,but the CTE values of three kinds of thermoplastic modified epoxy resin were all higher than neat epoxy above the Tg range.