高透波低导热聚酰亚胺复合材料的制备与性能研究

Preparation and properties of polyimide composites with high wave-transmitting and low thermal conductivity

以一种含氟聚酰亚胺树脂为树脂基体,石英纤维布为增强体,采用热压罐成型方法制备了石英增强聚酰亚胺树脂基高透波低导热复合材料。首先通过DSC及黏温曲线对含氟聚酰亚胺的固化行为进行初步判定,然后通过研究不同固化工艺参数对复合材料力学性能的影响,确定了最优固化工艺参数,最后研究了复合材料的导热性能、介电性能及其在宽频范围内的透波性能。结果表明:聚酰亚胺复合材料成型过程中的最优加压温度为300℃、成型压力不小于1.00 MPa、固化温度为370~390℃。按照最优工艺参数制备的聚酰亚胺复合材料在25~450℃范围内导热系数为0.57 W/(m·K),且在7~18 GHz内具有优异的介电性能,透波率达83%以上,满足透波功能材料的使用要求。

A quartz reinforced polyimide resin composite with high wave-transmitting and low thermal conductivity was prepared by the autoclave molding process using a fluorine-containing polyimide resin as resin matrix and quartz fiber cloth as reinforcement.At first,the curing behavior of fluorine-containing polyimide was preliminarily determined by DSC and viscosity-temperature curve.Then the optimal curing process parameters was determined by studying the influences of different curing process parameters on the mechanical properties of the composites.At last,the thermal conductivity,dielectric properties,and wave-transmitting properties in a wide frequency range of the composites were investigated.The results show that during the molding process of polyimide composite,the optimal molding temperature is 300℃,the molding pressure is no less than 1.0 MPa,and the curing temperature is 370-390℃.The polyimide composite prepared according to the optimal molding process parameter has 0.57 W/(m·K) of thermal conductivity in the range of 25-450℃ and excellent dielectric performance in the range of 7-18 GHz,and its transmittance is more than 83%,which meets the application requirements of wave-transmitting functional materials.