Molecular Simulation Of Mechanical And Thermal Properties Of Fullerene Ball Reinforced Epoxy Composites

Fullerenes,as a kind of lightweight,high strength and high modulus nanomaterials,have excellent mechanical properties.Fullerenes are hollow molecules made entirely of carbon atoms that are spherical,ellipsoidal,cylindrical or tubular depending on the number of carbon atoms they contain.C₆₀ is the most abundant and easily obtained molecular configuration in the fullerene family.C₆₀ is a hollow spherical molecule with 30 carbon-carbon double bonds composed of 20 six-membered rings and 12 five-membered ring links made up of 60 carbon atoms,which has the same carbon six-membered ring structure as graphene.According to the structural characteristics of C₆₀ and above,the configuration of fullerene-ball-reinforced epoxy composite was proposed in this paper.The mechanical and thermal properties of fullerene-ballreinforced epoxy composite were studied by molecular dynamics method.At first,this paper constructed the fullerenes ball enhanced molecular model body,epoxy resin and curing agent by molecular dynamics simulation of solidification process has been crosslinked epoxy resin unit cell model,to embed the fullerenes ball in epoxy matrix obtained the unit cell model of fullerenes ball reinforced composites,and the resulting model structure optimization.By comparing and analyzing the density distribution curve and the radial distribution function curve of the epoxy resin unicell model and the composite unicell model,it was found that the addition of C₆₀ would reduce the density of the material and improve the probability density of c-H covalent bond and C-O covalent bond distribution in the material.Fullerenes ball reinforced composites was studied after tensile mechanical properties and compression mechanical properties,the study found that adding 7.33 wt % of C₆₀ composite materials tensile ultimate strength and tensile modulus of the pure epoxy resin respectively 30.18% and 14.28% of ascension,compress yield strength and compression modulus of the pure epoxy resin with 15.28% and 12.35% respectively.The effect of curing degree on the mechanical properties of composites was studied.It was found that the strength and modulus of composites increased with the increase of curing degree.The influence of the content of C₆₀ on the mechanical properties of composites was studied,and it was found that the strength and modulus of composites would increase first and then decrease with the increase of the content of C₆₀.Finally,the thermal conductivity of the epoxy composite reinforced by fullerene spheres was calculated by means of equilibrium molecular dynamics method.The results showed that the thermal conductivity of the composite with 7.33 wt% C₆₀ added was 20% higher than that of the pure epoxy resin.The effect of temperature on the thermal conductivity of fullerene spherical reinforced composites was studied.It was found that the thermal conductivity of the composites is directly proportional to the temperature,and the higher the temperature is,the greater the average azimuthal shift of the molecules in the materials is.The influence of the content of C₆₀ on the thermal conductivity of composite materials was studied.It was found that the thermal conductivity of composite materials increased first and then decreased with the increase of the content of C₆₀,and the content of C₆₀ would change the size of the average azimuth shift of molecules in the composite materials.