Bian Xingming, Tuo Rui, Yang Wei, Zhang Yiran, Xie Qing, Zha Junwei, Lin Jun, He Shaojian
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China.
State Key Laboratory of Advanced Power Transmission Technology, Global Energy Interconnection Research Institute, Beijing 102211, China.
Polymers (Basel). 2019 Sep 23;11(10):1548. doi: 10.3390/polym11101548.
Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high voltage insulation. In this work, carboxyl-terminated butadiene nitrile liquid rubber (CTBN) was used to toughen the boron nitride-epoxy hybrid system, and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated. The results showed that when the content of CTBN was 5-15 wt.%, the CTBN formed a dispersed island structure in the epoxy resin matrix. The toughness of the composite increased by about 32%, the breakdown strength was improved, and the thermal conductivity was about 160% higher than that of pure epoxy resin. As the CTBN content increased, the glass transition temperature and thermal stability of the composite decreased and the dielectric constant and the dielectric loss increased. When the CTBN content is 10-15 wt.%, a toughened epoxy composite material with better comprehensive properties is obtained.
填充型高导热环氧复合材料解决了环氧树脂本身导热率低的问题，但导热填料的加入降低了复合材料的力学性能，这限制了其在高压绝缘领域的应用。在本工作中，采用羧基封端的丁腈液体橡胶（CTBN）对氮化硼-环氧混合体系进行增韧，并研究了不同含量的CTBN对复合材料的力学性能、导热率、玻璃化转变温度、热稳定性和介电性能的影响。结果表明，当CTBN含量为5-15 wt.%时，CTBN在环氧树脂基体中形成分散的岛状结构。复合材料的韧性提高了约32%，击穿强度得到改善，导热率比纯环氧树脂高约160%。随着CTBN含量的增加，复合材料的玻璃化转变温度和热稳定性降低，介电常数和介电损耗增加。当CTBN含量为10-15 wt.%时，可获得综合性能较好的增韧环氧复合材料。
