Molecular Dynamics Simulation Study On Thermal Conductivity Of Graphene And H-BN/Epoxy Resin Nanocomposites

Epoxy resins have been widely in the fields of electrical appliances,pipeline,packaging manufacturing or packaging of electronic equipments.Due to the low thermal conductivity of epoxy resins,there are often many restrictions for its application.At present,how to improve the thermal conductivity of epoxy resins and its nanocomposites as much as possible with a small amount of doping fillers has became a hot and difficult issue in the field of researching in composites and engineering.In this paper,equilibrium molecular dynamics method and non-equilibrium molecular dynamics method have been used to study the addition of Diglycidyl ethers bisphenol A(DGEBA)and diaminodipheyl sulfone(3-3DDS)epoxy resins systems and research for effect of graphene and boron nitride nanofillers on thermal conductivity of DGEBA/DDS epoxy resins.The main content of this paper are as follow:(1)Programing for the automatic cross-linking reaction and annealing of DGEBA and DDS molecules through the perl language,and constructing the atoms of pure DGEBA/3-3DDS epoxy resins,graphene/epoxy nanocomposites and boron nitride/epoxy nanocomposites.Modeling and simulating the process of crosslinking reaction of epoxy resins.(2)The thermal conductivity of pure DGEBA/3-3DDS epoxy resins,graphene/epoxy nanocomposites and boron nitride/epoxy nanocomposites was calculated using the equilibrium molecular dynamics method.The simulation results are as follow:the thermal conductivity of pure epoxy resins is 0.2065Wm^-1K^-1.When the volume fraction of the fillers is about 10vol%,the thermal conductivity of graphene/epoxy nanocomposites is 0.2995Wm^-1K^-1 and the thermal conductivity of boron nitride/epoxy nanocomposites is 0.5678Wm^-1K^-1,which are basically consistent with the experimental results.The thermal conductivity of epoxy resins has been improved by adding graphene and boron nitride nanofillers into epoxy resins(3)The non-equilibrium molecular dynamics method was used to calculate the interfacial thermal resistance of graphene/epoxy nanocomposites and the interfacial thermal resistance of boron nitride/epoxy nanocomposites.The simulation results are as follows:the interfacial thermal resistance of graphene/epoxy nanocomposites is(4.48-8.43)×10^-9m²KW^-1,which is basically consistent with the experimental results;the interface thermal resistance of boron nitride/epoxy nanocomposites is(2.42-3.62)×10^-9m²KW^-1.The interface thermal resistance of graphene/epoxy nanocomposites and boron nitride/epoxy nanocomposites will decrease exponentially with the increasing in the number of graphene and boron nitride layers.(4)The thermal conduction mechanism of pure epoxy resins,graphene/epoxy nanocomposites,and boron nitride/epoxy nanocomposites is analyzed by using the phonon state density method.