Sri International

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

The Dow Chemical Company

Commtech International Management Corporation

Commtech International

James F Wolfe

Paul D Sybert

Joanne R Sybert

Fred E Arnold, Jr

Blake Wilson

Robert J Schmitt

David S Ross

Bock H Loo

Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.

Liquid crystalline polymer compositions process, and products

Novel liquid crystalline extended chain polymer compositions comprising a high concentration of one or more extended chain homopolymer(s), copolymer(s), or block polymer(s) and certain strong acids are prepared by admixing a high concentration of one or more selected homo- or hetero-bifunctional monomer(s) with or without oxidation protecting atoms or groups and one or more of a substantially non-oxidizing strong acid(s) having a high or low P.sub.2 O.sub.5 content. Such compositions are capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.

Liquid crystalline polymer compositions, process, and products

A method of nitrating resorcinol which is selective for the production of the 4,6-dinitro resorcinal isomer. A resorcinol-based starting material is admixed with a nitrating solution from which substantially all nitrogen dioxide and nitrous has been removed. The nitrating solution contains white fuming nitric acid, a nitrosonium ion control agent such as urea, and, optionally, concentrated sulfuric acid. The 4,6-dinitroresorcinal isomer is provided in yields of about 65-85% with minimal production of undesirable side products.

Process for preparing 4,6-dinitroresorcinol

Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared under conditions to exercise control of molecular weight as characterized by intrinsic visoscity. Such compositions are optically anisotropic (liquid crystlaline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at excptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.

Liquid crystalline polymer compositions, process and products

Liquid crystalline poly (2,6-benzothiazole) compositions, process, and

Thermally stable rod-like polymers comprised of poly {[benzo-(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, said polymers being referred to as 'PBT' and having the structure ##STR1## wherein n has an average value of about 50 to 100, together with the monomeric compound 2,5-diamino-1,4-benzenedithiol dihydrochloride. Said polymers are useful in the preparation of high modulus, high strength materials having excellent thermal stability.

Thermally stable rod-like polybenzobisthiazole polymers

p-Terphenylene-dicarboxylic acids in which aromatic groups are attached to the middle phenyl group of the terphenylene moiety. The compounds are useful as monomers in the preparation of rod-like, para-ordered aromatic heterocyclic polymers.

P-Terphenylene-dicarboxylic acids and their synthesis

Para-ordered aromatic heterocyclic polymers containing pendant phenyl groups along the polymer chain backbones. The polymers possess a high degree of thermal stability that renders them particularly useful in high temperature applications such as in the fabrication of plastics, composites and fibrous materials.

Growing community of inventors

Redwood City, CA, United States of America

James F Wolfe