Simulations Of The Mechanical Properties Of Polymer Matrix Nanocomposite Based On Materials Studio

Polymer matrix nanocomposites have attracted much attention because of their excellentproperties on mechanics, thermodynamics, electrics and optics. Due to the combination of therespective advantages of organic and inorganic materials, polymer matrix nanocomposites havemany valuable characteristics and that provide this kind of materials a wide range of applicationsin various fields. With the development of computer technology, the use of computer simulationhas become an increasingly common way of research. In this paper, molecular dynamic (MD)simulation method was employed to study the properties of pure polymer and polymericcomposites reinforced by nanoparticles.According to molecular dynamics theory，the Materials Studio software was used to buildthe molecular models of a polyimide single chain and a silica nanoparticle and the followingcontents were then considered.1. The single chain was used to build the initial periodic amorphous unit cell of purepolyimide and a reasonable cell was achieved after molecular dynamic calculations. Themagnitudes of the mechanical properties such as Young modulus, bulk modulus and Poissonratio of this cell were then obtained.2. Strains were applied on the directions of a,b,c sides of the pure polyimide unit cellrespectively and every stress corresponding to the strains was calculated. The stress-strainrelationships of this unit cell on X,Y,Z directions were drawn based on the results.3.5pure polyimide unit cells were structured by the same modeling and dynamicoptimization process, the mechanical properties of them were calculated and the mean valueswere also figured out.4. The unit cell model of polyimide nanocomposite reinforced by silica nanoparticle wasbuild and the mechanical properties of this cell were obtained. Strains were applied on the celland the corresponding stresses were calculated. The stress-strain relationships were also figured out.5nanocomposite models were structured and the mean values of the mechanical propertieswere calculated. These values were compared with those of the pure polyimide unit cells and theeffect of the nanoparticles on the mechanical properties was analyzed.