The physical properties of polymers are very much dictated by where the operating temperature lies with respect to the transition temperature between glassy and rubbery states. The precise identification of this glass transition temperature, Tg, is critical in assessing the feasibility of a polymer for a given application. In this book, the behavior of polymers near their Tg and the capability of predicting Tg using theoretical and empirical models is assessed. While all polymers undergo structural relaxation at various temperatures both nearly above and below Tg, practical assessment of a...