氮化硅晶须/氮化铝颗粒/聚酰亚胺复合材料的制备及性能

Preparation and properties of AlN/Si_(3)N_(4)/PI composites

高导热聚酰亚胺复合材料因具有良好的综合性能,在集成电子电路、航空航天等领域具有较好的发展前景。采用导热系数较高的氮化硅晶须和氮化铝颗粒作为无机填料,用钛酸酯偶联剂进行表面改性,原位合成氮化硅晶须/氮化铝颗粒聚酰亚胺(AlN/Si_(3)N_(4)/PI)复合材料。采用扫描电子显微镜(SEM)、Hot Disk试验仪和拉伸试验机对复合材料进行结构和性能表征。结果表明:当AlN/Si_(3)N_(4)体积比为4:2时,复合填料在基体中可形成较好的导热网络,当填料的体积分数达到30%时,复合材料的导热系数最大,为0.84 W/(m·K)。复合材料的力学性能随填料含量的增加而降低,耐热性能随填料含量的增加而提高。

High thermal conductivity polyimide composites have good development prospects in integrated electronic circuits,aerospace and other fields because of their good comprehensive properties.In this paper,silicon nitride whiskers and aluminum nitride particles with high thermal conductivity were selected as inorganic fillers,and surface modification was made with titanate coupling agent,and silicon nitride whiskers/aluminum nitride particles/polyimide(AlN/Si_(3)N_(4)/PI)composite films were synthesized in situ.The structure and properties of the composite films were characterized by scanning electron microscopy(SEM),Hot Disk tester and tensile tester.The results show that when the volume ratio of AlN/Si_(3)N_(4) is 4:2,the composite filler forms a good thermal conductivity network in the matrix.When the total filler volume fraction reaches 30%,the thermal conductivity of the composite film reaches the maximum of 0.84 W/(m·K).The mechanical properties of the composites decrease with the increase of filler content,and the heat resistance increases with the increase of filler content.