非共价改性石墨烯的制备及环氧树脂复合材料导热性能

Preparation of Non-Covalent Modified Graphene and Its Thermal Conductivity of Epoxy Resin Composites

采用非共价键表面修饰制备了聚乙烯吡咯烷酮(PVP)改性的石墨烯(GR@PVP),通过共混方式将其作为填料与环氧树脂(EP)复合得到了不同填充量的EP/GR复合材料。红外光谱和热重分析结果表明,聚乙烯吡咯烷酮成功接枝到石墨烯表面。动态力学热分析和热性能测试结果表明,EP/GR@PVP复合材料的储能模量、玻璃化转变温度和损耗因子峰高度均比EP/GR复合材料有所降低,表明聚乙烯吡咯烷酮增强了环氧树脂复合材料的柔韧性。采用扫描电子显微镜观察复合材料断面形貌,GR@PVP在环氧树脂中分散均匀,且与基体相容性好。当填料质量分数为2.0%时,EP/GR@PVP复合材料的热导率比纯EP和EP/GR复合材料分别提高了205.3%和52.6%,25℃EP复合材料的表观黏度为13.29 Pa·s,符合电子封装材料对复合材料加工黏度的需求(<20 Pa·s)。其研究为进一步制备高导热、低黏度的电子封装材料提供了一种简便的方法。

Polyvinylpyrrolidone(PVP)modified graphene(GR@PVP)was prepared by non-covalent bond surface modification.EP/GR composites with different filling amounts were obtained by blending it with epoxy resin(EP).The results of FT-IR and thermogravimetric analysis(TGA)show that polyvinylpyrrolidone was successfully grafted onto the surface of graphene.The results of DMA and TG show that the storage modulus,glass transition temperature and loss factor peak height of EP/GR@PVP composites are lower than those of EP/GR composites,indicating that polyvinylpyrrolidone enhances the flexibility of epoxy resin composites.The fracture morphology of the composites was observed by scanning electron microscopy.GR@PVP is uniformly dispersed in epoxy resin and has good compatibility with the matrix.When the filler mass fraction is 2.0%,the thermal conductivity of EP/GR@PVP composites is 205.3%and 52.6%higher than that of pure EP and EP/GR composites,respectively.The apparent viscosity of EP/GR@PVP-2 composites at 25℃(13.29 Pa·s)meets the requirement of electronic packaging materials for the processing viscosity of composites(<20 Pa·s).This paper provided a simple method for further preparation of electronic packaging materials with high thermal conductivity and low viscosity.