THERMODYNAMIC ANALYSIS OF FLUID SORPTION IN POLYMERS

摘要

Fluid sorption in polymers has been treated by the term of irreversible (rational) thermodynamics. A thermodynamic model for heterogeneous mixture involving sorption and the other processes (such as diffusion, internal interactions, such internal changes of polymer network as swelling, consolidation, plasticization etc.) is proposed. In this model creation of sorption species and internal state changes are presented by the internal state variables. The formation of sorption species occurs on certain sites by weak internal interactions (association). Interaction centers i.e., sorption sites may be different polar groups or polar induced groups on the polymer molecular chains. By this model some complex relationships between sorption potential, diffusion, sorption kinetics, polymer network changes kinetics, chemical affinity energy of internal state changes and properties of polymer network are obtained. Some experimental results of fluid sorption in polymer networks have been interpreted by this model. Sorption mechanism and sorption isotherms are considered.