摘要
基于在聚合物基体中添加导热物质,构筑致密导热网络可以改善基体的低导热性,引入泡沫作为骨架,利用其三维支架结构,结合2D片状无机填料氮化硼作为导热填料,在环氧树脂中构筑导热网络.通过研究2种具有不同骨架结构和组成的泡沫:聚氨酯泡沫和纳米三聚氰胺(蜜胺)泡沫,采取先浸渍后热压固化的方法,获得具有高热导率的环氧树脂基复合材料.最后,当氮化硼含量为41 wt%,热压固化时的压缩比为90%时,复合材料面穿方向热导率可高达3.88 W·m^–1·K^–1.
It is a traditional method to improve the thermal conductivity of matrix by adding fillers. However, it is a great challenge to construct a dense heat conduction network in composite material. The current researches on building thermal conductive network is to combine different fillers through structure design for achieving high thermal conductivity with the lowest possible filler content. Due to the electrical insulation requirements of electronic equipment, hexagonal boron nitride(h-BN) has been extensively studied as an inorganic thermal conductive filler. It has a layer structure that shows a relatively high TC of 300 W·m^–1·K^–1 in the h-BN planar direction. In this study, the foam was introduced into the epoxy resin as a skeleton, and thermal conductive network was constructed by immersing the BN/E51 mixture into the foam. By comparing the hot deformation behavior of two kinds of foams with different structures and compositions: polyurethane foam(PF) and nanomelamine(melamine) foam(MF), epoxy resin-based composites with high thermal conductivity were obtained by hot press curing under the right compression ratio. PF has a large single arm size and good elastic deformation ability, but it is easy to become a barrier between BN, which is bad for forming thermal conductive path after compression. However, MF has a small single arm size and can be broken into four needle-like scaffold structures after compression. The needle-like scaffold structure promotes the good dispersion of BN, and finally forms a thermal path of BN throughout the material, which plays a key role in improving the thermal conductivity of the composite. As a result, MF-BN/E51 showed an excellent thermal conductivity of 3.88 W·m^–1·K^–1 at 41 wt% BN load when the degree of hot pressing was 90%. It provides a new way for the composites to achieve a higher thermal conductivity with a less filler load.
作者
闫蓉
张玲
李春忠
Rong Yan;Ling Zhang;Chun-zhong Li(Key Laboratory for Ultrafine Materials of Ministry of Education,Shanghai Engineering Research Center of Hierarchical Nanomaterials,School of Materials Science and Engineering,East China University of Science&Technology,Shanghai 200237)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2019年第11期1209-1217,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51673063,21878092,21838003,91834301)
上海市优秀学术带头人机会(项目号19XD1401400)
中央高校基本科研业务费专项(项目号222201718002)资助项目
关键词
聚氨酯泡沫
蜜胺泡沫
氮化硼
导热网络
热导率
Polyurethane foam
Melamine foam
Boron nitride
Thermal conductive network
Thermal conductivity
