Thermal properties of polymer-penetrant mixtures

Abstract Quantitative modeling for the design of polymer foaming processes requires the knowledge of thermal properties of the mixtures of polymer and blowing agents. In fact, the presence of a penetrant within a polymer significantly affects the glass transition and crystallization/melting temperature of the starting neat polymer. Moreover, also energy transport parameters are affected, with particular reference to thermal conductivity. In this chapter, the phenomenology of glass transition in polymer-penetrant systems is first discussed, illustrating several theoretical approaches aimed at its interpretation. The effect of the presence of penetrant on the crystallization/melting behavior of the mixtures is then presented, introducing the recent advancements in their theoretical interpretation. Further discussion of these issues, in the perspective of the foaming process, is provided in Chapter 13 . Finally, experimental and modeling results for thermal conductivity of polymer-penetrant mixtures are discussed in some detail. All these aspects have been considered including the case of contact of a polymer with a physical blowing agent in the supercritical fluid state.