Patents by Inventor Dawn M. Crawford

Dawn M. Crawford has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Highly sulfonated block copolymer hydrogels and uses thereof
    Patent number: 7307127
    Abstract: A block copolymer composition AB is provided that has pendent groups —RZ extending from the A copolymer on at least 70 mol % of the A monomers, where R and Z are each an ionic species. The composition is included in a semipermeable membrane for use in a direct methanol fuel cell. Also described are articles of protective apparel comprising the composition which advantageously has barrier properties as well as superior water vapor transport properties.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: December 11, 2007
    Assignee: United States of America as represented by the Secretary of the Army
    Inventors: Eugene Napadensky, Yossef A. Elabd, Dawn M. Crawford, James M. Sloan
  • Self-assembled sulfonated block copolymer semipermeable membrane and uses therefor
    Patent number: 6579948
    Abstract: A semipermeable membrane that is capable of remaining flexible at a temperature of at least −60° C. is selective to liquid penetrants depending on the size and polarity of the penetrants, and more specifically, the membrane has sufficient selectivity so as to be capable of allowing water to diffuse therethrough at a higher rate than virtually all organic liquids having a molecular weight higher than that of methanol. The semipermeable membrane, which is produced from an unsulfonated block copolymer having polystyrene and polyisobutylene segments, includes a sulfonated block copolymer including poly (styrene-co-styrene sulfonic acid) segments and polyisobutylene segments. Prior to modification by sulfonation, the unsulfonated polystyrene and polyisobutylene block copolymer includes polystyrene monomer in an amount of from 5% to 90% by weight of the total unsulfonated block copolymer.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: June 17, 2003
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Nora C. Beck Tan, Dawn M. Crawford, James M. Sloan, Eugene Napadensky
  • Rubber compound for tracked vehicle track pads
    Patent number: 5264290
    Abstract: A highly improved elastomeric composition, process, and articles made thef, wherein the novel composition is characterized by greatly increased wear longevity, thermomechanical stability, highly improved tear and tensile strength at high temperature usage, in addition to high resistance to burning in open flame, as well as high resistance to cutting, chipping, cracking and crack propagation particularly in product use for tank track pads and other related track system elastomeric component products; wherein the improved composition is a unique combination of its respective polymer, filler, curing and antidegradant system, in which the polymer system either consists of about 100 parts by weight of highly saturated nitrile polymer or of various novel blends of the highly saturated usually in majority amounts together with minority amounts of carboxylated nitrile, with or without additional minority or near equal parts of nitrile rubber; and wherein the curing system may include various blends of from between ab
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: November 23, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Paul Touchet, Gumersindo Rodriguez, Paul E. Gatza, D. Patrick Butler, Dawn M. Crawford, Alan R. Teets, Henry O. Feuer, David P. Flanagan