The Dow Chemical Company

Marinda L Wu

John F Voeks

Linneaus C Dorman

Walter L Vaughn

Charles W Martin

Victor E Meyer

Terry D Gordon

The invention relates to improved gas separation membranes fabricated from a polymer containing a hydrocarbon backbone and pendant metal ionomer groups wherein the pendant metal ionomer groups contain cations of alkali metals, alkaline earth metals, or transition metals bound to pendant --CO.sub.2.sup.-. The metal modified membranes result in improved gas selectivities with comparable or improved permeabilities over the unmodified membranes. The membranes may be used to separate gas mixtures such as carbon dioxide and methane or oxygen and nitrogen.

Metal ionomer membranes for gas separation

The invention relates to a composition useful for producing a modifying adherent layer on a passive polymeric material, said composition comprising (A) a fluorinated ester substituted alkoxy cellulose having, on the average, between about 1.0 to 2.99 of the three reactive hydroxyl groups of each glucose unit present as alkoxy groups, and the remainder of the reactive hydroxyl groups of each glucose unit present as a fluoroester group of the formula: ##STR1## wherein R.sub.f is branched perfluoroalkyl comprising 3 to 20 carbon atoms; or --(CF.sub.2).sub.n CF.sub.2 --Q, wherein Q is hydrogen of fluorine; n is an integer from 1 to 19; or ##STR2## wherein X is selected from the group consisting of --F, --CF.sub.3 and --CF.sub.2 Cl, Y is --F, --Cl, --CF.sub.2 Cl or perfluoroalkyl having from 1 to 10 carbon atoms, Z is --F, --Cl, --CF.sub.3 or CF.sub.2 Cl, and m is an integer from 1 to 12; and (B) an organic solvent. The composition may be in an enclosed container having integral fluid delivery means such as a gas-pressurized container or a container having a manual pump.

Composition for modifying polymeric surfaces and articles produced

The invention relates to a process of separating gases using a membrane fabricated from a polymer containing a perfluorinated backbone and pendant hydrated metal ionomer groups wherein the pendant hydrated metal ionomer groups contain cations of alkali metals, alkaline earth metals, or transition metals bound to SO.sub.3.sup.-. The hydrated membranes have improved gas permeabilities with comparable gas selectivities over the unhydrated membranes. The membranes may be used to separate gas mixtures containing such gases as carbon dioxide and methane.

Hydrated metal ionomer membranes for gas separation

The invention relates to improved gas separation membranes fabricated from cyclic iminoether modified alpha-olefin/carboxylic acid copolymers. The modified membranes possess improved gas selectivities and/or permeabilities over the unmodified membranes. The membranes may be used to separate gas mixtures containing such gases as oxygen, nitrogen, methane, and carbon dioxide.

Gas separation membranes from polymers containing a hydrocarbon backbone

The invention is a method of separating a gas comprising helium, oxygen, nitrogen or carbon dioxide from a mixture of gases containing helium, oxygen, nitrogen or carbon dioxide wherein the method comprises

Gas separations using membranes comprising perfluorinated polymers with

This invention relates to an improved process to produce composite polymeric materials and an article having an adherent surface layer. More specifically, the invention describes a process for producing a modifying adherent layer on a passive polymeric material, the layer comprising a fluorinated ester substituted alkoxy cellulose having, on the average, between about 1.0 to 2.99 of the three reactive hydroxyl groups of each glucose unit present as alkoxy groups, and the remainder of between about 0.01 to 2.00 of the reactive hydroxyl groups of each glucose unit present as a fluoroester group of the formula: ##STR1## wherein R.sub.f is branched perfluoroalkyl comprising 3 to 20 carbon atoms; or --(CF.sub.2).sub.n CF.sub.2 --Q, wherein Q is hydrogen or fluorine, n is an integer from 1 to 19; or ##STR2##

Methods of modifying polymeric surfaces and articles produced thereby

A dramatic reduction in the time required to fine-grind high borate solder glasses is achieved. In the prior art method, the glass is ball-milled in the presence of an amine for about seven days or more. It has now been discovered that by first rod-milling such glasses for a period of from about 1/2 to about 24 hours, the time required for the 'amine grind' can be shortened to a period of from about 1 to 3 days. A further improvement is that rod milling eliminates the laborious sieving procedure previously employed to ensure the absence of undesirably large particles in the feed to the amine grinding operation.

Growing community of inventors

San Ramon, CA, United States of America

Marinda L Wu