以蓖麻油和多亚甲基多苯基多异氰酸酯(PAPI)为主要原料,通过改性剂KH-550对导热填料六方氮化硼(h-BN)进行改性制备导热聚氨酯灌封胶,并研究了改性BN(k-BN)对灌封胶性能的影响。结果表明,h-BN改性处理有效改善了其在聚氨酯灌封胶中的分散性并且降低基料的黏度;k-BN的加入显著提高了灌封胶的导热性能。当k-BN填充质量分数为50%时,导热系数为0.51 W/(m·K),比纯PU提高了180%,且较好地维持了灌封胶材料的力学性能,能够满足灌封胶对强度及形变的要求。热重(TG)分析结果表明填充k-BN后灌封胶的热稳定性得到提升。

Taking castor oil and polymethylene polyphenyl polyisocyanate (PAPI) as main raw materials,a kind of high thermal conductivity polyurethane potting sealant is prepared through modifying hexahexagonal boron nitride (h-BN),a thermal conductive filler,by KH-550 silane.The influences of modified k-BN on the performance of potting sealant are studied.Results demonstrate that h-BN modification enhances effectively k-BN's dispersibility in polyurethane potting sealant and reduces the viscosity of matrix material.The addition of k-BN improves significantly the thermal conductivity of potting sealant.With a k-BN filling mass fraction of 50%,the thermal conductivity of the prepared sealant is 0.51 W/(m·K),which is 180% higher than that of pure polyurethane.Furthermore,the mechanical property of the prepared sealant is well maintained to meet strength and deformation requirements for potting sealant application.Thermogravimetric analysis reveals an improved thermal stability after k-BN filling.

孙双双(1999-),女,硕士生,研究方向为聚氨酯导热材料,1261154983@qq.com