Barrier performance of two fluoroelastomers, vinylidene fluoride-hexafluoropropylene copolymer (Fluorel) and propylene-tetrafluorethylene copolymer (Aflas) were investigated by liquid immersion and incremental vapor sorption with acetone. The equilibrium weight uptake of liquid acetone is 105% in Fluorel, which is four times of that in Aflas. The sorption isotherms do not appear to be readily described by the Flory-Rehner equation even with a polymer-solvent interaction parameter in a virial expansion form. The sorption kinetics are that of Fickian when the solvent activity is low but become non-isothermal condition caused by heat of sorption. In both elastomers, the diffusion coefficient exhibits concentration dependency, which usually can be explained by free volume theories. However, Fujita's theory appears fail to explain the behaviour at higher concentration levels.
|Original language||English (US)|
|Number of pages||2|
|Journal||Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering|
|State||Published - Dec 1 1993|
|Event||Proceedings of the American Chemical Society Division of Polymeric Materials - Science and Engineering - Chicago, IL, USA|
Duration: Jun 11 1993 → Jun 11 1993