Patents by Inventor Larry L. Fewell

Larry L. Fewell 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).

  • Patent number: 4288585
    Abstract: Carboranyl-substituted polyphosphazenes are prepared by heat polymerizing a carboranyl halocyclophosphazene at 250.degree. C. for about 120 hours in the absence of oxygen and moisture. The cyclophosphazene is obtained by allowing a lithium carborane, e.g. the reaction product of methyl-o-carborane with n-butyllithium in ethyl ether, to react with e.g. hexachlorocyclotriphosphazene at ambient temperatures and in anhydrous conditions. For greater stability in the presence of moisture, the chlorine substituents of the polymer are then replaced by aryloxy or alkoxy groups, such as CF.sub.3 CH.sub.2 O--.The new substantially inorganic polymers are thermally stable materials which produce a high char yield when exposed to extreme temperatures, and can thus serve to insulate less heat and fire resistant substances.
    Type: Grant
    Filed: March 12, 1980
    Date of Patent: September 8, 1981
    Inventors: Robert A. Administrator of the National Aeronatuics and Space Administration, with respect to an invention of Frosch, Harry R. Allcock, John P. O'Brien, Angelo G. Scopelianos, Larry L. Fewell
  • Patent number: 4276403
    Abstract: Polydihalophosphazenes, e.g. --N.dbd.P(Cl).sub.2 ].sub.n, are allowed to react at ambient temperatures for at least one hour with a lithium carborane in a suitable inert solvent. The remaining chlorine substituents of the carboranyl polyphosphazene are then replaced with aryloxy or alkoxy groups to enhance moisture resistance. The polymers give a high char yield when exposed to extreme heat and flame and can be used as insulation.
    Type: Grant
    Filed: March 12, 1980
    Date of Patent: June 30, 1981
    Inventors: Robert A. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Frosch, Harry R. Allcock, John P. O'Brien, Angelo G. Scopelianos, Larry L. Fewell