熔融模压制备PVDF/石墨烯复合材料及其性能研究

Study on Properties of PVDF/Graphene Composites Prepared by Melt Compression Molding

以聚偏二氟乙烯(PVDF)树脂为基体、石墨烯为填料,通过高速混合机混合作用,经分散剂、润湿剂、表面活性剂、相容剂等组分协同作用,使石墨烯在PVDF中分散均匀,然后经熔融模压成型,制得PVDF/石墨烯复合材料。利用扫描电子显微镜和透射电子显微镜研究了复合材料的微观形貌,并研究了石墨烯含量、制备工艺、助剂及PVDF树脂牌号对复合材料介电性能、导电性能和导热性能的影响。结果表明,采用的助剂体系和高速混合、熔融模压的制备方法能使石墨烯以微片的形态均匀地分散在PVDF树脂基体中,形成良好的功能网络结构;复合材料介电常数、电导率、介电损耗、体积电阻率和导热系数均随石墨烯含量增加而增大;当石墨烯质量分数达到2.0%左右时,复合材料的介电和导电特性均发生突变,向高介电、高导电材料转变,而当石墨烯质量分数达到5.0%左右时,复合材料开始向高导热材料转变;制备工艺和PVDF树脂牌号对复合材料热、电性能的影响则相对较小。

Graphene was uniformly dispersed in poly（vinylidene fluoride） （PVDF） by the synergetic action of dispersant, wetting agent, surfactants and compatibilizer through the high speed mixer, then PVDF / graphene composites were prepared by melt compression molding. The influences of grapheme content, preparing methods, agents and resin grades on the dielectric properties, conductivity and thermal performances of the composites were investigated. The results indicate that grapheme nanosheet can be uniformly dispersed in PVDF to form a function network structure through the used agents system and the preparing method including high speed mixing and melt compression molding. The dielectric constant, electrical conductivity, dielectric loss, volume resistivity and thermal conductivity all increase with the increase of the content of graphene. The inflection point of the electrical properties and thermal performance of the composites occur when the mass fraction of graphene was 2.0% and 5.0% respectively, then the composites turn into high dielectric property, high conductivity and high thermal conductivity materials. The influences of preparing methods and resin grades on the electrical and thermal properties are not obvious.