摘要
越来越高的电热密度以及电力设备小型化的趋势需要电力设备的绝缘材料具备更好的导热性能。针对传统环氧树脂(epoxy,EP)导热率过低的缺陷,通过剥离六方氮化硼的方法制备了氮化硼纳米片(boron nitride nanosheet,BNNS),将其作为填料掺入环氧树脂得到了复合材料(EP–BN)。测试结果证明,BNNS能有效改善环氧树脂的导热性能,其掺杂体积分数为25%的EP–BN导热率相对于EP提升了528%。通过测量材料的介电谱发现,BNNS加入后,EP–BN的相对介电常数和介电损耗均增大,但两者涨幅并不大;同时,两者均随着温度的升高而增加。分析材料的热刺激电流获得其陷阱参数,发现由于BNNS的存在,EP–BN的陷阱深度变浅,从而降低了极化电荷产生所需要的能量,表现为相对介电常数和介电损耗增加。温度的变化对材料的陷阱深度几乎无影响,但温度的升高促进了陷阱电荷量的产生,表现为材料相对介电常数和介电损耗的增大。
With the development of electrothermal density and miniaturization of power equipment,the insulating materials of power equipment are required to possess a better thermal conductivity.In order to solve the problem of low thermal conductivity of traditional epoxy resin(EP),boron nitride nanosheep(BNNS)was prepared by stripping hexagonal boron nitride and then incorporated into epoxy to obtain nanocomposites.The test results show that BNNS can effectively improve the thermal conductivity of epoxy resin,and the thermal conductivity of EP–BN with a volume fraction of 25%doping ratio is increased by 528%compared with that of pure epoxy resin.By measuring the dielectric spectrum of the composites,it is found that the addition of BNNS will increase the dielectric constant and dielectric loss of the composites,but the increase amplitude is not significant,and the increase of temperature will also increase the dielectric constant and dielectric loss of the composites.The trap parameters are obtained by analyzing the thermal stimulated current of the composites.BNNS can shallow the trap depth of EP–BN so as to reduce the energy needed for polarization charge generation,resulting in an increase of the dielectric constant and dielectric loss.The increase of temperature will hardly affect the dielectric depth of the material,but can lead to the increase of the amount of trapped charge,which is also manifested as the increase of dielectric constant and dielectric loss of the EP–BN.
作者
张晓星
胡国雄
伍云健
唐炬
ZHANG Xiaoxing;HU Guoxiong;WU Yunjian;TANG Ju(School of Electrical and Automation,Wuhan University,Wuhan 430072,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第2期645-651,共7页
High Voltage Engineering
基金
国家重点研发计划(2017YFB0903805)。
关键词
氮化硼纳米片
环氧树脂
导热性能
介电性能
热刺激电流
boron nitride nanosheet
epoxy resin
thermal conductivity
dielectric properties
thermally stimulated current
