An experimental approach to the development and validation of Group Interaction Modelling of polymer properties

Group Interaction Modelling (GIM) is a modelling framework for predicting properties of polymers from their chemical structure. Hitherto, the predictive power of GIM has been hindered by its semi-empirical components, reliance on limited data, and gaps in physical detail. The author’s doctoral research involved several experimental techniques that have been deployed to measure thermomechanical properties of a single-source polymer across a wide range of temperatures and spanning 13 orders of magnitude in rate. The model framework was thus systematically tested and informed to improve its predictive power, with physically derived additional considerations. The author’s choice of the single-source material of study was Bisphenol A Polycarbonate.

The author will present an overview of the experiments used in this research, involving both dynamic compression techniques, such as split Hopkinson pressure bar measurements, and other techniques to obtain measurements of bulk properties like the coefficient of thermal expansion, thermal transport properties, and mechanical moduli. Comparisons of model predictions with experimental measurements will be shown and the main findings of this research, in terms of model improvements, will be highlighted.

Overall, this research has contributed to a significantly improved tool for predicting polymer properties from their chemical structure, with the improvements backed by physical concepts and verified with experimental measurements. To demonstrate this, the author will present some examples involving polymers other than the single-source polycarbonate and discuss possible utilisations of GIM to understand structural details of polymers, including an example of a more complex bio-derived material.