PPTA@ZnO NWs的功能化修饰及导热绝缘纸基材料的制备与研究

Preparation of Thermal Conductive Insulation Paper Based Composite with Functionalized PPTA@ZnO Nanowires

为了提高芳纶纤维纸基材料的导热性,通过水热合成法在对位芳纶纤维(PPTA)表面生长氧化锌纳米线(ZnO NWs),进一步用硅烷偶联剂KH550对PPTA@ZnO NWs进行功能化修饰,采用湿法造纸技术制备PPTA@ZnO NWs-KH550纸基复合材料并研究其导热性能、绝缘性能及力学性能。结果表明,ZnO NWs成功地均匀包覆在PPTA表面。与PPTA纸基复合材料相比,PPTA@ZnO NWs纸基复合材料的导热系数可达0.455W/(m·K),提高115.64%,且介电强度满足绝缘要求。经硅烷偶联剂KH550功能化修饰后,PPTA@ZnO NWs-KH550纸基复合材料导热系数较修饰前基本保持不变,呈现优异的绝缘性和良好的力学性能,介电强度增加3.69%,拉伸强度提高58.75%。

Aramid fiber based paper materials have been widely used in electronic communication,military industry,aerospace and other fields owing to the excellent heat resistance,good electrical insulation capability and mechanical properties.However,the low thermal conductivity of aramid fiber largely limited the application of aramid fiber based paper materials in electronic devices,power systems,etc.Accordingly,an efficient work to improve the thermal conductivity of aramid fiber based paper materials was presented.In this paper,ZnO nanowires were grown on surface of para-aramid fiber(PPTA)by hydrothermal synthesis and were further functionalized with silane coupling agent KH550.Then,the PPTA@ZnO NWs-KH550 paper based composite was prepared by conventional papermaking process and thermal conductivity,insulation and mechanical properties of as-prepared composite were studied.Results showed that ZnO nanowires were successfully coated on the surface of PPTA.The thermal conductivity of PPTA@ZnO NWs paper based composite reached 0.455 W/(m·K),increased by 115.64%compared with PPTA paper based composites.The dielectric strength of PPTA@ZnO NWs paper based composite mets the insulation requirements.After modified by silane coupling agent KH550,the thermal conductivity of PPTA@ZnO NWs-KH550 paper based composite was almost unchanged,the dielectric strength increased by 3.69%and the tensile strength increased by 58.75%,which indicated the composite exhibited excellent insulation and good mechanical properties.