Prediction of polyimide materials with high glass-transition temperatures

The prediction of chemical structures that possess higher glass-transition temperatures (T-g's) is crucial for designing polyimides. Because of a lack of suitable parameters, several estimation methods cannot be used for this purpose. In this study, therefore, we used molecular dynamic simulation wi th the DREIDING II force field to predict Tg's for polyimides. Simulated re sults indicated a good agreement with experimental observations. A barrier analysis of the bridging bonds between moieties along the main-chain backbo ne showed a correlation between T-g and the barrier height. This proved to be helpful in a preliminary selection before the molecular dynamic simulati on for accelerating the process of research and development on new polyimid es. (C) 2001 John Wiley & Sons, Inc.