The Dow Chemical Company

The University of Bath

William P Carl

Bobby R Ezzell

William A Mod

Jeffrey D Birdwell

Alan J Cisar

Emmett L Tasset

Keith R Plowman

Bruce R Smith

Robert E Aikman, Jr

Timothy J Rehg

Charles S Eastland

Larry W Davis

John M Mcintyre

A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

Composite fuel cell membranes

The invention is a method for forming polymer composite films using removable substrates comprising:

Method for forming polymer composite films using removable substrates

The invention is a method for forming polymer composite films using a removable substrate comprising:

Method for forming polymer composite films using a removable substrate

The invention is a sulfonic fluoropolymer having a fluoropolymer backbone having pendant groups attached thereto and represented by the general formula:

Low equivalent weight sulfonic fluoropolymers

The invention is a process for producing a modified polytetrafluoroethylene which comprises polymerizing tetrafluoroethylene in an aqueous medium containing a dispersing agent with a polymerization initiator source and then, copolymerizing tetrafluoroethylene one or more fluorinated modifiers having an acid functional group or a functional group which is convertible to the acid group as a copolymerizable modifier in the presence of the resulting polytetrafluoroethylene to a polymerization point past the Kraft point to produce highly porous, fibrous, stratified fluoropolymers having cores made of homopolymer of poly-tetrafluoroethylene coated with sheath layers which are made of a copolymer of polytetrafluoroethylene and one or more modifiers. The invention also includes a highly porous, fibrous, stratified fluoropolymer having a plurality of interconnected, fibrous-like projections wherein the stratified fluoropolymer has a core layer of polytetrafluoroethylene substantially completely covered by a copolymer of polytetrafluoroethylene and a fluorocarbon modifier.

Stratified fibrous fluoropolymer compositions and process for forming

Novel vinyl ethers are prepared in decarboxylation reactions of novel acid fluoride compounds according to the following reaction: ##STR1## wherein a is 0 or an integer greater than 0;

Process to produce novel fluorocarbon vinyl ethers and resulting polymers

The invention is a method for forming composite polymer films comprising:

Method for forming composite polymer films

The invention is a method for sizing polytetrafluoroethylene fabrics comprising:

Method for sizing polytretrafluoroethylene fabrics

The invention is a method for sizing polyterafluoroethylene fibers, yarns, or threads comprising:

Method for sizing polytetrafluoroethylene fibers, yarn, or threads

The invention is a process for making a high surface area, self-supporting catalyst suitable for use as an acid catalyst comprising:

Process for forming a shaped porous fluorinated polymer catalyst and the

The invention is a method for coating polytetrafluoroethylene fabrics, fibers, yarns, or threads comprising:

Method for sizing and hydrolyzing polytetrafluoroethylene fabrics,

Compounds represented by the general formulas ##STR1## are prepared by reacting halofluoropropylene oxides with fluorinated acid fluorides and ketones. These compounds may be decarboxylated to form useful monomers, ##STR2## wherein a=to 3;

Preparation, decarboxylation and polymerization of novel acid fluorides

Method for sizing polytetrafluoroethylene fabrics

The invention is a method for forming a supported membrane film comprising:

Growing community of inventors

Angleton, TX, United States of America

William P Carl