Study the Effect of the Polymerization Degree of Molecule on Influencing Mechanical Property of Epoxy Resin by Molecular Simulation

Bisphenol A epoxy resin is widely used in electrical equipment. The mechanical property is closely connected to the operation of epoxy resin in power equipment, which is related to the molecular structure, such as molecular polymerization degree (PD). However, how the PD influence mechanical property of epoxy resin is still unclear. In this work, we studied the effect of molecular PD on influencing mechanical property of epoxy resin by molecular simulation. Based on Material Studio, epoxy molecules with PD of 0, 1 and 2 were established and the crosslinked structures were constructed by methyltetrahydrophthalic anhydride. Based on the crosslinked structures, the crosslinked densities, free volume fractions, glass transition temperatures and elastic moduluses were computed. It was found that the molecule with lower PD held a greater crosslinked density, a lower free volume fraction and a greater glass transition temperature. Meanwhile, the low PD also led to a greater Young's and shear modulus, and a lower bulk modulus.