E.i. Dupont De Nemours and Company

United States of America As Represented by the Secretary of the Air Force

Irene Greenwald Plotzker

David Richard Corbin

Joel David Citron

Marion G Waggoner

Kenneth George Sharp

Donald R Uhlmann

Thomas M Ford

Samuel Tacitus D'Arcangelis

Leighton H Peebles, Jr

Joan H Cranmer

Steven Gust Cottis

A polymer composition and method for reducing the permeability of gases through molded polymeric containers and films by incorporating into the polymer from which the container or film is formed an effective amount of a barrier-enhancing additive, such as monoesters of hydroxybenzoic acid and hydroxynaphthoic acid.

Method and composition for improving gas barrier properties of polymeric containers and films

Composition containing liquid crystalline polymer

A laminar shaped article which exhibits substantial improvement in the fluid barrier properties over the laminate of the prior art. The article comprises a heterogeneous blend of: (a) polyolefin with (b) a melt blend of a nylon and a polyvinyl alcohol component, and a compatibilizer(c), which is either: i) a mixture of two different alkylcarboxyl-substituted polyolefins which serves as a compatibilizer; or ii) a small amount of alkylcarboxyl-substituted polyolefin with a small amount of grafted maleic anhydride moieties; or iii) a high weight percent of alkylcarboxyl-substituted polyolefin with a high graft level of grafted maleic anhydride moieties.

Laminar articles of polyolefin and nylon/polyvinyl alcohol blend and

Disclosed herein are thermotropic liquid crystalline poly(ester-amides) containing repeat units derived from alipatic diamines and other monomers, such as aromatic diols, aromatic dicarboxylic acids, aromatic hydroxycarboxylic acids, and optionally aliphatic diols. The polymers are particularly useful as films and in multilayer structures as barrier layers because of their relatively low permeability to various compounds.

Liquid crystalline poly(ester-amides)

A fabrication process is disclosed that achieves a higher density carbon-bon article, than the prior art processes by maintaining a vertical temperature gradient in a reservoir of pitch (e.g. 550.degree. C. at the bottom to 250.degree. C. at the top) into which a carbon fiber preform is immersed. The use of the vertical temperature gradient results in a reservoir of hot fluid pitch around the upper end of the preform during pitch impregnation of the preform. This permits the fluid pitch to drain down by gravity into the interstices of the carbon fiber and the hardening pitch below. The next step of the process involves gradually increasing the pitch-hardening temperature from bottom to top to harden the pitch from bottom to top. Thereafter, the impregnated preform is carbonized at high temperature. This method takes advantage of the thermal conductivity of the carbon fibers and does not require extremely high pressures. In fact, a high pressure would be a detriment since it results in closed pores. The process of the present disclosure depends on the development of large, connected pores that can be more easily filled. This manner results in the production of suitable carbonized billets in a fraction of the time currently required and using much less energy.

Process for carbon-carbon composite fabrication

A protective garment fabricated at least in part from a composite fabric which contains a layer of a highly fluorinated ion exchange polymer having sulfonic acid multivalent metal ion salt functional groups.

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Wilmington, DE, United States of America

Irene Greenwald Plotzker