Other

The United States of America As Represented by the Administrator of the

The United States of America As Represented by the United States

The United States of America As Represented by the Administrator

Robert W Rosser

Robert A Frosch

Hanoi Kwong

Ibrahim M Shalhoub

Timothy S Chen

Chung-Heng Cheng

Kazimiera J Paciorek

Reinhold H Kratzer

William D Kray

Thomas I Ito

Roger A Korus

Theodore Psarras

Leonard O Ross

Mark S Taylor

Perfluoroether triazine elastomers having improved properties are prepared from oligomeric imidoylamidines that have, in turn, been prepared by the process of (a) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (b) isolating the perfluorodiamidine, (c) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating steps (a), (b), and (c) to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed. The elastomers can be fashioned into seals, gaskets, sealing components and the like.

Perfluoro (Imidoylamidine) diamidines

Perfluoroether triazine elastomers having improved properties and utility in seals, gaskets, sealing components and the like are prepared from oligomeric imidoylamidines that have, in turn, been prepared by the process of (a) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (b) isolating the perfluorodiamidine, (c) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating steps (a), (b), and (c) to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed.

Process for preparing perfluorotriazine elastomers and precursors thereof

Addition of controlled amounts of perfluorinated alkyl ether diacyl fluoride to epoxy resin systems prior to cure results in a formulation which, when cured with or without reinforcing, exhibits improved energy absorbing properties.

Fluoroether modified epoxy composites

Fluorinated alkyl or alkylether 1,2,4-oxadiazole compounds are prepared by cyclizing the corresponding alkyl or alkylether imidoylamidoximes in vacuo or in an inert atmosphere at a temperature within the range of 40.degree. to 100.degree. C. for a period of 8 to 144 hours in the presence of an acid compound which can accept ammonia to form a salt. The imidoylamidoximes usable in this process may be either polymeric or nonpolymeric. The products, when polymeric, have excellent heat, chemical and solvent resistance.

Preparation of perfluorinated 1,2,4-oxadiazoles

New 1,1,1-triaryl-2,2,2-trifluoroethanes in which the aryl radicals carry one or more substitutents have been prepared by condensation of trifluoroacetophenones with substituted phenyl compounds in the presence of catalytic quantities of trifluoromethylsulfonic acid. The reaction can be carried out under reflux in toluene or, for strikingly better results in certain cases, reactants are simply stirred at room temperature for about 24 to 48 hours.

1,1,1-Triaryl-2,2,2-trifluoroethanes and process for their synthesis

New crosslinked 1,2,4-oxadiazole elastomers have been prepared by thermally condensing (a) monomer having the formula H.sub.2 N(HON)C-R-Q, wherein Q is a triazine ring-forming group such as nitrile or amidine or a mixture of such group with amidoxime, or (b) a mixture of said monomer with R[C(NOH)NH.sub.2 ].sub.2, with R in these formulas standing for a bivalent organic radical having the formula

Preparation of crosslinked 1,2,4-oxadiazole polymer

New crosslinked 1,2,4-oxadiazole elastomers have been prepared by thermally condensing (a) monomer having the formula H.sub.2 N(HON)C--R--Q, wherein Q is a triazine rig-forming group such as nitrile or amidine or a mixture of such group with amidoxime, or (b) a mixture of said monomer with R[C(NOH)NH.sub.2 ].sub.2, with R in these formulas standing for a bivalent organic radical having the formula

Bifunctional monomers having terminal oxime and cyano or amidine groups

New crosslinked 1,2,4-oxadiazole elastomers have been prepared by thermally condensing (a) monomer having the formula H.sub.2 N(HON)C-R-Q, wherein Q is a triazine ring-forming group such as nitrile or amidine, or (b) a mixture of said monomer with R[C(NOH)NH.sub.2 ].sub.2, with R in these formulas standing for a bivalent organic radical having the formula

1,2,4-Oxadiazole elastomers

New crosslinked elastomeric polytriazines have been prepared by a 4-step procedure which consists of: (1) forming a poly(imidoylamidine) by the reaction under reflux conditions of anhydrous ammonia with certain perfluorinated alkyl or alkylether dinitriles; (2) forming a linear polytriazine by cyclizing the imidoylamidine linkages by reaction with certain perfluorinated alkyl or alkylether acid anhydrides or halides; (3) extending the linear polytriazine chain by further refluxing in anhydrous ammonia; and (4) heating to cyclize the new imidoylamidine linkages and thereby crosslink the polymer.

Process for the preparation of fluorine containing crosslinked

New perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups are prepared by the reaction of perfluoroalkyl dinitriles with ammonia to form poly(imidoylamidines), followed by the cyclization of the imidoylamidine groups with, e.g. various mixtures of a perfluoroacyl fluoride with an .omega.-iodoperfluoroacyl fluoride. The polytriazines obtained can be cured by heat which causes crosslinking at the iododifluoromethyl groups by elimination of iodine and formation of carbon-to-carbon bonds.

Perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups

Diamidoxime monomers having the formula: ##STR1## are intermolecularly and thermally condensed to form a heat and chemical resistant polymer containing 1,2,4-oxadiazole linkages and having the formula: ##STR2## wherein R represents identical bivalent organic radicals or any combination of bivalent organic radicals selected from the group consisting of --(CX.sub.2).sub.p --, wherein p ranges from 2 to 8 when X is fluorine and 2 to 18 when X is hydrogen, chlorine, nitro or aryl; arylene; and an oligometric or polymeric radical prepared by reacting a dicarboxylic acid halide with a fluorinated epoxide and having the formula:

Growing community of inventors

San Jose, CA, United States of America

Robert W Rosser