Abstract: A multilayer cation exchange membrane for use in a chloralkali process comprising an carboxylate layer comprising a fluorinated ionomer containing carboxylate groups on one side of the membrane, an exterior sulfonate layer comprising a fluorinated ionomer containing sulfonate groups on the side of the membrane opposite the carboxylate layer, and an interior sulfonate layer comprising a fluorinated ionomer containing to sulfonate groups between the carboxylate layer and the exterior sulfonate layer, the exterior sulfonate layer having an ion exchange ratio greater than about 11.3, and the interior sulfonate layer having an ion exchange ratio less than about 11.

Abstract: This invention relates to ionomers and to ionically conductive compositions formed therefrom. The ionomers comprise polymerized units of monomers A and monomers B, wherein monomers A are perfluoro dioxole or perfluoro dioxolane monomers, and the monomers B are functionalized perfluoro olefins having fluoroalkyl sulfonyl, fluoroalkyl sulfonate or fluoroalkyl sulfonic acid pendant groups, CF2?CF(O)[CF2]nSO2X. The ionically conductive compositions of the invention are useful in fuel cells, electrolysis cells, ion exchange membranes, sensors, electrochemical capacitors, and modified electrodes.

Abstract: Crosslinkable fluoropolymers and crosslinked fluoropolymers prepared from select fluorinated monomers by dimerization and trimerization. Also disclosed are proton conductive membranes of these crosslinked fluoropolymers.

Abstract: Crosslinkable polymers and crosslinked fluoropolymers are prepared from selected fluorinated dienes and monomers containing Br and I. Also disclosed are proton conductive membranes of these crosslinked fluoropolymers.

Abstract: A composite, porous, liquid-permeable article is provided which is a multilayer structure of discrete, bonded layers of porous, expanded polytetrafluoroethylene (EPTFE). The composite has its interior and exterior surfaces coated with a perfluoro ion exchange polymer to render the composite hydrophilic so as to resist gas locking in aqueous media. Initially, the diaphragm may also contain a water-soluble surfactant to assist in initial water penetration into the pores of the composite. An improved electrolytic cell is provided having the composite diaphragm as the porous separator in the electrolysis of alkali halide solutions. The diaphragm is also useful as an improved filter medium.

Abstract: A composite, porous, liquid-permeable article is provided which is a multilayer structure of discrete, bonded layers of porous, expanded polytetrafluoroethylene (EPTFE), which composite has its interior and exterior surfaces coated with a perfluoro ion exchange polymer to render the composite hydrophilic so as to resist gas locking in aqueous media wherein a composite diaphragm made therefrom, may also contain a water-soluble surfactant to assist in initial water penetration into the pores of the composite whereby an improved electrolytic cell is provided having the composite diaphragm as the porous separator in the electrolysis of alkali halide solutions and wherein the diaphragm is also useful as an improved filter medium.

Abstract: A dimensionally stable, composite membrane of a microporous film in laminar contact with a continuous perfluoro ion exchange resin layer is provided. The composite membrane comprises a continuous perfluoro ion exchange polymer layer which has an original, as-prepared, length, width and thickness, the ion exchange polymer layer being in laminar attachment to a film of a microporous material, preferably porous, expanded polytetrafluoroethylene (EPTFE), the microporous film having essentially the same length and width as the as-prepared continuous perfluoro ion exchange layer. The perfluoro ion exchange layer is swollen with a hydrophilic liquid to an extent that the hydrophilic liquid exceeds 20% by weight of the swollen, continuous perfluoro ion exchange layer. The swollen ion exchange layer exhibits less than a 5% increase in either length or width from its original, as-prepared, state, but it exhibits a substantial increase in thickness over its original, as-prepared, state.

Abstract: An abrasion-resistant, tear-resistant, multilayer composite membrane, useful in electrolysis, is provided comprising a continuous perfluoro ion exchange polymer film attached to a reinforcing fabric by means of a porous, expanded polytetrafluoroethylene (EPTFE) interlayer. The fabric and EPTFE are rendered hydrophilic and non-gas-locking by coating the interior and exterior surfaces thereof with a perfluoro ion exchange resin of equivalent weight less than 1000. The composite preferably is treated with an ionic perfluoro surfactant. Also provided is a multilayer composite according to the above in which the continuous perfluoro ion exchange film is itself a multilayer construction of a perfluorosulfonate polymer and a thin layer of perfluorocarboxylate polymer in which the perfluorosulfonate polymer interfaces with the EPTFE and the interior and exterior surfaces of the EPTFE and fabric are coated with perfluorosulfonate polymer.