石墨微片/硼粉对环氧树脂体系性能的影响

Effect of Graphite Microchip/Boron Powder on Properties of Modified Epoxy Resin System

采用石墨微片和硼粉的复合体系制备了一种环氧树脂导电胶膜。通过绝缘测试仪、拉力试验机等对胶膜的电性能及力学性能进行了表征。结果表明,随着石墨与硼粉量的增加,电阻值和剪切强度呈明显下降的趋势。当石墨、硼粉用量分别为14.5 phr和20 phr时,胶膜的电阻值约为100 MΩ,剪切强度约为20 MPa。扫描电镜照片发现石墨微片呈片层结构分布在树脂体系中,有利于导电网络的构建;胶膜的体积电阻率和表面电阻率分别为7.29×10^7Ω·m、1.26×10^9Ω;胶膜的玻璃化转变温度约为125℃;5%热失重温度达到了347℃;固化后的胶膜具有保持自身形状的特性,且在120℃具有较宽的加工工艺窗口;该导电胶膜有望在复合材料防雷击保护等方面获得应用。

Graphite microchip and boron powder composites were adopted to prepare a kind of epoxy resin conductive adhesive film.The electrical and mechanical properties of the films were studied by the insulation tester and tension testing machine.The results show that the resistance value and shear strength decrease obviously with the amount of graphite and boron powder increasing.When the dosage of the graphite and boron powder is 14.5 phr and 20 phr respectively,the resistance of the film is about 100 MΩand the shear strength is about 20 MPa.Scanning electron microscope(SEM)images show that the graphite microchips are distributed by lamellar layer in the resin system,which is beneficial for the construction of conductive networks.The volume resistivity and the surface resistivity of the film are 7.29×107Ω·m and 1.26×109Ω,respectively.The glass transition temperature of the film is about 125℃and the 5%mass loss temperature reaches 347℃.The cured film has the characteristic of maintaining its own shapeand represents a wide processing window under 120℃.The conductive film is expected to be applied in the composite protection against lightning strikes.