Atomistic molecular dynamics in polyethylene oxide and polymethyl methacrylate blends having significantly different glass transition temperatures

The highly asymmetric polymer blends, polyethylene oxide and polymethyl methacrylate systems, having extraordinary different original glass transition temperature (T-g) values, have been examined by the fully atomistic molecular dynamics simulations. We have determined densities against temperatures after establishing the conditions of models to clarify the composition-dependent behavior of the systems. The relations show the intermediate region in addition to the T-g1 and T-g2, the high and low-temperature T-g values, respectively. The trend found in the polymer blends is reproduced well from the weighted sum of plots for both homopolymers by assuming the additivity of local volumes. The dynamics of the polymer blend exhibited similar behavior with ionic systems but with different time scales. These results open new understandings for the physical meanings of the T-g in polymer blends and their relation with dynamics.

Automated summary

In this study, highly asymmetric polymer blends with significantly different original glass transition temperatures were examined using molecular dynamics simulations. The composition-dependent behavior of the systems was clarified by establishing models and studying the density against temperature. The results showed that the dynamics of the polymer blends exhibited similar behavior with ionic systems but with different time scales.