The free-volume idea as it relates to diffusion in polymers has proved to be successful to describe diffusion in several polymer-solvent systems. This talk will focus on several aspects and applications of free-volume ideas – namely the equivalence between the free-volume approach and the Arrhenius approach, understanding migration of small molecules in polymers, solvent induced crystal formation in polymers, and examples of using free-volume based approaches to troubleshoot industrial problems.

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