基于纳米氮化硼-聚氨酯/玻纤三维骨架的环氧导热复合材料性能研究  

Performance investigation of epoxy thermal conductive composite based on nano boron nitride-polyurethane/fiberglass three-dimensional structure

作　　者：许培俊[1] 王乾 郑欣 李寒煜 郭新良 刘荣海 XU Peijun;WANG Qian;ZHENG Xin;LI Hanyu;GUO Xinliang;LIU Ronghai(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China;Electric Power Research Institute of Yunnan Power Grid Co.,Ltd.,Kunming 650217,China)

机构地区：[1]长安大学材料科学与工程学院,西安710064 [2]云南电网有限责任公司电力科学研究院,昆明650217

出　　处：《复合材料科学与工程》2024年第11期5-13,共9页Composites Science and Engineering

基　　金：国家自然科学基金面上项目(51978072);陕西省重点研发计划项目(2022GY-371);长安大学中央高校基本科研业务费专项资助(300102312404)。

摘　　要：纤维增强环氧树脂比重小,比强度高,固化收缩率低,耐腐蚀性能优异,被广泛应用于航空航天等领域。受到特殊加工工艺和电子电力行业散热需求的影响,产品对材料导热性能的要求日益严格。本研究以阻燃聚氨酯开孔泡沫(PUF)为模板,在其中引入纳米氮化硼(BNNS)进行改性,并采用浸渍-热压成型法制得低填充氮化硼-聚氨酯/玻纤/环氧导热复合材料,以研究不同BNNS用量对复合材料热性能和电气性能的影响。结果表明,BNNS原位生长在PUF的三维骨架表面,随着BNNS用量的增加,复合材料的热性能显著提高。当氮化硼纳米片含量为1vol%时,复合材料热导率可达0.53 W/(m·K),提高了103%,同时其线膨胀系数降低了77.6%。当BNNS含量为0.5vol%时,复合材料玻璃化转变温度提升了13.5℃,并具有最佳的热稳定性和力学性能。此外,得益于氮化硼自身优异的绝缘性,复合材料的体积电阻率提升至7.2×10^(15)Ω·cm,且耐电弧性能也有明显提升。Fiber-reinforced epoxy resin composite is widely employed in aerospace and other industries due to its low specific gravity,high specific strength,low curing shrinkage,and excellent corrosion resistance.However,the demand for thermal conductivity in this material has become increasingly stringent due to its special processing techniques and the heat dissipation requirements of the electronics and power industries.In this study,flame-retardant polyurethane open-cell foam(PUF)was used as a template;and nano boron nitride(BNNS)was introduced to modify this material.A low-loading boron nitride-polyurethane/fiberglass/epoxy thermal conductive composite was prepared using an impregnation-hot pressing method to investigate the effects of different BNNS contents on the thermal and electrical properties of the composite material.The results show that BNNS grows in situ on the three-dimensional skeleton surface of PUF,and as the BNNS content increases,the thermal performance of the composite material significantly improves.When the content of boron nitride nanosheets is 1vol%,the thermal conductivity of the composite material reaches 0.53 W/(m·K),which represents a 103%increase,while the coefficient of linear expansion decreases by 77.6%.With a BNNS content of 0.5vol%,the glass transition temperature of the composite material increases by 13.5℃,and it exhibits optimal thermal stability and mechanical properties.Moreover,thanks to the excellent insulation properties of boron nitride,the volume resistivity of the composite material is elevated to 7.2×10^(15)Ω·cm,and its arc resistance is significantly enhanced.

关 键 词：导热复合材料 聚氨酯泡沫 氮化硼纳米片 耐电弧性能 绝缘性能 

分 类 号：TB332[一般工业技术—材料科学与工程]