改性氧化石墨烯对环氧树脂基复合材料热膨胀系数影响的研究

Influence of modified graphene oxide on the coefficient of thermal expansion of epoxy composite

环氧树脂(EP)热膨胀系数(CTE)为65×10^(-6)℃^(-1),碳纤维(CF)CTE为-12×10^(-6)℃^(-1),因此降低EP的CTE是提高碳纤维增强环氧树脂(CF/EP)复合材料低温使用性能的关键。采用氧化石墨烯(GO)和四氧化三铁改性氧化石墨烯(Fe_3O_4-GO)修饰EP,研究了GO及Fe_3O_4-GO对EP基体CTE的影响。结果表明:由于Fe_3O_4-GO表面的官能团可与EP基体形成共价键,从而加强了与EP基体的界面作用;相对于纯EP,GO和Fe_3O_4-GO改性EP的玻璃化转变温度(Tg)分别升高了3.71℃和5.74℃;相对于纯EP,GO和Fe_3O_4-GO改性EP在Tg下的CTE值分别降低了23.77%和33.61%,但在Tg上的CTE值均高于纯EP。

Coefficient of thermal expansion(CTE)of epoxy and carbon fiber are 65×10^-6℃-1 and-12×10^-6℃-1,respectively.CTE has a big influence on the property of carbon fiber reinforced epoxy laminate and how to decrease CTE value of epoxy matrix is the key to improve its property at cryogenic temperature.Graphene oxide(GO)and Fe3O4 modified graphene oxide(Fe3O4-GO)were applied to modified epoxy and its CTE value was studied.The results showed that covalent bond was formed between filler and epoxy,which strengthen the interfacial bonding between filler and epoxy matrix.Glass transition temperatures(Tg)of GO and Fe3O4-GO modified epoxy resin were all improved.In comparison to neat epoxy,CTE values of GO and Fe3O4-GO modified epoxy resin belowTgrange were decreased 23.77% and 33.61%,respectively,but CTE values of GO and Fe3O4-GO modified epoxy resin were all higher than neat epoxy when above Tgrange.