Thermal and mechanical properties and micro-mechanism of SiO_(2)/epoxy nanodielectrics  

作　　者：Tian-Yu Wang Gui-Xin Zhang Da-Yu Li 王天宇;张贵新;李大雨(Department of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]Department of Electrical Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Chinese Physics B》2021年第12期613-619,共7页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant.Nos.2017YFB0902503 and 2016YFB0900802)。

摘　　要：In addition to electrical insulation properties,the thermal properties of nanodielectrics,such as glass transition temperature,thermal expansion coefficients,thermal conductivity,and mechanical properties,including Young's modulus,bulk modulus,and shear modulus,are also very important.This paper describes the molecular dynamics simulations of epoxy resin doped with SiO_(2)nanoparticles and with SiO_(2)nanoparticles that have been surface grafted with hexamethyldisilazane(HMDS)at 10%and 20%grafting rates.The results show that surface grafting can improve certain thermal and mechanical properties of the system.Our analysis indicates that the improved thermal performance occurs because the formation of thermal chains becomes easier after the surface grafting treatment.The improved mechanical properties originate from two causes.First,doping with SiO_(2)nanoparticles inhibits the degree of movement of molecular chains in the system.Second,the surface grafting treatment weakens the molecular repulsion between SiO_(2)and epoxy resin,and the van der Waals excluded region becomes thinner.Thus,the compatibility between SiO_(2)nanoparticles and polymers is improved by the grafting treatment.The analysis method and conclusions in this paper provide guidance and reference for the future studies of the thermal and mechanical properties of nanodielectrics.

关 键 词：nanodielectric surface grafting treatment molecular dynamics simulation interface properties 

分 类 号：TQ323.5[化学工程—合成树脂塑料工业] TB332[一般工业技术—材料科学与工程]