Studies on syntheses and permeabilities of special polymer membranes. 28. Permeation characteristics and structure of interpolymer membranes from poly (vinylidene fluoride) and poly (styrene sulfonic acid)

Abstract

The permeation characteristics of poly (vinylidene fluoride) -poly (styrene sulfonic acid) interpolymer membranes in the separation of polymers, poly (ethylene glycols), from their aqueous solutions were investigated under various conditions. The permeation characteristics were influenced markedly by the casting solution composition and operating temperature. It was seen by scanning electron photomicrographs that the changes of ratio of poly (vinylidene fluoride) -poly (styrene sulfonic acid) were related to the changes of microporous structure of the resulting membranes. The permeation rates for aqueous solutions of poly (ethylene glycols) were greater than for pure water. It was found that this phenomenon was dependent on the physical and chemical natures of the membranes and the permeating molecules. The permeation mechanism through the interpolymer membranes was not only the viscous flow.