Investigation by molecular dynamics simulation of the glass transition temperature and elastic properties of amorphous polymers PMMA, PMAAM and PMMA co PMAAM copolymers

In this study, the glass transition temperatures T g of both polymethacrylamide (PMAAM) and polymethylmethacrylate (PMMA) polymers, and their related copolymers P(MMA (1 − x ) MAAM ( x ) ) at various composition ( x ) were calculated, using molecular dynamics simulation. Calculations are performed using AMBER force field to describe the potential energies of homopolymers and copolymers structures. We have employed the static method to determine the bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio at temperature 300 K. Our results stay in good agreement with the experimental ones. The T g of PMAAM (213.3 °C) is greater than T g of PMMA (115.9 °C) which is explained by the difference in their chemical structures, while the T g increases linearly with increasing composition ( x ) in copolymer P(MMA (1 − x ) MAAM ( x ) ). From our findings, we have investigated the viscoelastic behavior at different regions to predict the effect of temperature on the mechanical properties of these polymers and copolymers.