Study of the structure and glass transition behavior of epoxy polymers using molecular dynamics

Recently، great attention has been focused on epoxy polymers in different industrial and scientific activities، owing to superior mechanical properties and their stability in different environmental conditions. In this study، the molecular dynamics method was used to study the structure of cross-linked epoxy polymers and predict glass their transition temperature (Tg). The epoxy polymer with a certain degree of cross linking was constructed through the previously proposed cross linking procedure. A temperature cycle (300-600 K) with a constant rate was then applied to the cross-linked epoxy، and a rough estimate of the glass transition region was obtained through mean squared displacement curves. Thereafter، variation of density in terms of temperature was utilized to precisely calculate Tg. The estimated Tg was found to be in good agreement with experimental observations. Radial distribution function was finally used to investigate the effects of temperature and cross linking on the local structure of simulated polymer.