具有相隔离结构的聚苯乙烯/氮化硼绝缘导热复合材料的制备及研究

Preparation and Study of Insulating Conductive Composites with Phase Isolated Structure

以通用级聚苯乙烯(GPPS)树脂为基底,苯乙烯-乙烯-丁二烯-苯乙烯共聚物(SEBS)-环己烷溶液为胶黏剂,六方氮化硼(BN)为导热填料,首先利用胶黏剂均匀包裹基底树脂,然后让六方氮化硼紧密地包覆在上面,通过这种新型的胶黏剂法制备具有相隔离结构的GPPS/BN绝缘导热复合材料。通过扫描电子显微镜(SEM)观察样品的形貌,广角X射线衍射仪器(WAXD)分析导热填料的取向,以及热分析仪对样品进行导热系数的测定。结果表明,随着导热填料的不断添加,导热复合材料的导热系数先是平稳升高,达到一定阈值后,逾渗效应显现,导热系数急速上升;当BN质量分数为40%时,导热系数可提升1 129%。相比传统加工方法,胶黏剂法可让导热网络更加清晰、填料取向更明显,对导热性能的提升更加高效。

With general purpose polystyrene （GPPS） resin as the base material, styrene-ethylbutylene- styrene copolymer （SEBS） -cyclohexane solution as the adhesive, hexagonal boron nitride （BN） as the thermal conductive filler, the insulating thermal conductive composite materials with isolated structure was prepared by a new type of binder-mixing method. With the addition of BN, the thermal conductive coefficient of composites increased stably first, then rose rapidly after reaching a certain threshold caused by permeability effect. The results show that the thermal conductivity of the composites increases with the increasing of BN, and the thermal conductive coefficient of composites increases to 1129% of pure GPPS resin when the mass fraction of the BN is 40%. Compared with the traditional processing methods, composites prepared by binder-mixing method has a more clear thermal conductive pathway, and a better orientation of BN.