Gas Permeation Properties of Poly(1,1‘-dihydroperfluorooctyl acrylate), Poly(1,1‘-dihydroperfluorooctyl methacrylate), and Poly(styrene)-<i>b</i>-poly(1,1‘-dihydroperfluorooctyl acrylate) Block Copolymers

Abstract

The permeabilities of rubbery poly(1,1‘-dihydroperfluorooctyl acrylate) (PFOA), glassy poly(1,1‘-dihydroperfluorooctyl methacrylate) (PFOMA), and poly(styrene)- b -poly(1,1‘-dihydroperfluorooctyl acrylate) (PS- b -PFOA) diblock copolymers to N 2, O 2, H 2, CH 4, C 2 H 6, and CO 2 at 446 kPa and to C 3 H 8 at 308 kPa are reported as a function of temperature. In general, PFOMA has lower fractional free volume, smaller gas permeability coefficients, and larger activation energies of permeation than PFOA, consistent with the more restricted long-range segmental mobility of PFOMA. The PS- b -PFOA copolymers exhibit complex microphase-separated morphologies, and their gas permeability coefficients are intermediate between those of glassy PS and rubbery PFOA, decreasing in magnitude with increasing PS content.