MOTION OF SORBED GASES IN POLYMERS

The mobility of sorbed gases in polymers is an interesting scientific problem with important technological implications. Motional mechanisms for penetrant diffusion are considered to depend strongly on whether the polymer matrix is in the rubbery or glassy state. The dual-mode model, which has been employed by a large number of polymer chemists and engineers, is now under scrutiny by some investigators. Early results of a few NMR experiments and computer simulations are beginning to shed new light on the motional dynamics of both the penetrants and polymer chains.