磁性氮化硼取向导热环氧树脂的制备和性能

Preparation and Properties of Heat-Conducting Epoxy Resins Based on the Oriented Magnetic Boron Nitride

为了在低导热填料含量下提升环氧树脂(EP)的热导率并保持EP原有性能,在氮化硼纳米片(BNNS)上通过共沉淀法引入磁性四氧化三铁(Fe_(3)O_(4))颗粒制备了磁性氮化硼纳米片(mBNNS),以EP为基体,在外加磁场下以mBNNS为填料制备导热环氧树脂(mBNNS-EP)复合材料。对mBNNS的结构、磁响应性和其在EP中的取向度以及mBNNS-EP复合材料的断面形貌、导热性能、热稳定性、绝缘性能和力学性能进行分析和表征。X射线衍射(XRD)和扫描电子显微镜(SEM)测试结果分别证明Fe_(3)O_(4)在BNNS表面的生成和mBNNS在EP中的良好取向。与EP相比,mBNNS-EP复合材料的热导率随着mBNNS含量的增加而升高,20%-mBNNS-EP复合材料的热导率最高,达到了1.239 W/(m·K)。mBNNS-EP复合材料的热分解温度超过303℃,玻璃化转变温度(T_(g))高于130℃,弯曲强度大于56.93 MPa,表明mBNNS-EP复合材料具有良好的热稳定性和力学性能。mBNNS在EP中的垂直取向使mBNNS-EP复合材料的热导率大幅提升,且mBNNS-EP复合材料基本维持了EP的其他性能。

To improve the thermal conductivity of epoxy resin(EP)while maintaining its original properties at a low heat-conducting filler content,magnetic boron nitride nanosheets(mBNNSs)were prepared by introducing magnetic ferric oxide(Fe_(3)O_(4))particles onto boron nitride nanosheets(BNNSs)through a coprecipitation method.Under the external magnetic field,heat-conducting epoxy resin(mBNNSs-EP)composite materials were prepared by using EP as the matrix and mBNNSs as the filler.The structures,magnetic responsiveness,and orientation of mBNNSs in EP,along with the cross-sectional morphologies,heat-conducting,thermal stability,insulation,and mechanical properties of mBNNSs-EP composite materials,were analyzed and characterized.X-ray powder diffraction(XRD)and scanning electron microscope(SEM)results respectively confirm the synthesis of Fe_(3)O_(4)on the surface of BNNSs and the good orientation of mBNNSs in EP.Compared with EP,the thermal conductivity of the mBNNSs-EP composite materials rises as the mBNNSs content increases.The thermal conductivity of 20%-mBNNSs-EP composite material is the highest,reaching 1.239 W/(m·K).The heat decomposition temperature of mBNNSs-EP composite material exceeds 303℃,the glass transition temperature(T_(g))is over 130℃,and the bending strength is over 56.93 MPa,indicating that this mBNNSs-EP composite material has good thermal stability and mechanical properties.The vertical orientation of mBNNSs in EP significantly enhances the thermal conductivity of mBNNSs-EP composite material,and mBNNSs-EP composites basically maintain other properties of EP.