六方氮化硼/碳化硅晶须填充改性聚酰亚胺导热绝缘复合材料的制备及表征  

Preparation and Characterization of Thermal Conductive and Electrical Insulating Polyimide Molding Composites modified by h-BN/SiCw

作　　者：徐广锐 XU Guangrui

机构地区：[1]上海市塑料研究所有限公司,上海201700 [2]上海计算化学与化工工程技术研究中心,上海201100

出　　处：《上海化工》2020年第5期2-6,共5页Shanghai Chemical Industry

摘　　要：采用固相共混方法将六方氮化硼(h-BN)和碳化硅晶须(SiCw)作为导热填料对单醚酐型聚酰亚胺(PI)模塑粉进行改性,然后通过热模压工艺制备PI导热绝缘复合模压材料,并对其性能进行表征。测试结果表明:h-BN可以有效提高模塑料导热性能、热性能和电绝缘性能,但会降低材料力学性能;SiCw可以有效提高复合材料导热性能、热性能和力学性能,但会显著降低电绝缘性能。将h-BN/SiCw复配使用,在显著提高复合材料导热性能和热性能的同时又可保持其良好的力学性能和电绝缘性能。添加30%(质量分数)h-BN/SiCw(3/1),复合材料导热系数提高至1.21 W/(m·K),是未改性PI材料的4.84倍,弯曲强度为142MPa,体积电阻率为1.27×10^14Ω·cm,线性热膨胀系数(CTE)显著降低为55.6μm/(m·℃)。In this work,polyimide powders were modified using hexagonal boron nitride(h-BN)and/or silicon carbide whisker(SiCw)through simple solid-phase blending method and new polyimide composites with thermal conductivity and electrical insulating properties were prepared via hot pressing process.The mechanical properties,thermal conductivity,thermal properties and electrical insulation properties were characterized.Results indicated that,h-BN effectively improved the thermal conductivity,thermal properties and electrical insulation properties,but largely reduced the mechanical properties of PI molding composites.SiCw greatly enhanced the thermal conductivity,thermal properties and mechanical properties,but largely weakened the mechanical properties of composites.The combination of h-BN/SiCw could raise the thermal conductivity and thermal performance of the composite while maintaining good mechanical properties and electrical insulation properties.While the total filler content reached 30%with h-BN/SiCw mass ration of 3/1,thermal conductivity of the PI molding composites was up to 1.21 W/(m·K),4.84 folds of pure PI,the bending strength and volume resistivity were 142 MPa and 1.27×10^14Ω·cm,respectively.Meanwhile,its coefficient of linear thermal expansion(CTE)was significantly reduced to 55.6μm/(m·℃).

关 键 词：聚酰亚胺 导热 绝缘 六方氮化硼 碳化硅晶须 复合模压材料 

分 类 号：TQ324[化学工程—合成树脂塑料工业]