William R Alston

US Patent:

48451673, Jul 4, 1989

Filed:

Oct 29, 1986

Appl. No.:

6/924470

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C08G 7310

US Classification:

528353

Abstract:

A condensation polyimide containing a 1,1,1-triaryl-2,2,2-trifluoroethane structure, other related condensation polyimides and process for their preparation, which comprises polymerization of a cyclic dianhydride with a diamine.

US Patent:

61038644, Aug 15, 2000

Filed:

Jan 14, 1999

Appl. No.:

9/231890

Inventors:

William B. Alston - Medina OH
Gloria S. Gahn - Columbia Station OH

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C08G 7310
C08G 6926

US Classification:

528353

Abstract:

The polyimides are derived from solutions of at least one low-boiling organic solvent, e. g. isopropanol containing a mixture of polyimide-forming monomers. The monomeric solutions have an extended shelf life at ambient (room) temperatures as high as 80. degree. C. and consist essentially of a mixture of monoalkyl ester-acids, alkyl diester-diacids and aromatic polyamines wherein the alkyl radicals of the ester-acids are derived from lower molecular weight aliphatic secondary alcohols having 3 to 5 carbon atoms per molecule such as isopropanol, secondary butanol, 2-methyl-3-butanol, 2 pentanol or 3-pentanol. The solutions of the polyimide-forming monomers have a substantially improved shelf-life and are particularly useful in the aerospace and aeronautical industry for the preparation of polyimide reinforced fiber composites such as the polyimide cured carbon composites used in jet engines, missiles, and for other high temperature applications.

US Patent:

48851167, Dec 5, 1989

Filed:

Feb 23, 1988

Appl. No.:

7/159071

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C 1516
C09B 1104

US Classification:

562413

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

US Patent:

53347331, Aug 2, 1994

Filed:

Jan 17, 1992

Appl. No.:

7/822240

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C 1516

US Classification:

552114

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

US Patent:

47583800, Jul 19, 1988

Filed:

Oct 29, 1986

Appl. No.:

6/924474

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C 1516
C07D23702

US Classification:

260389

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

US Patent:

58615407, Jan 19, 1999

Filed:

Apr 15, 1994

Appl. No.:

8/228541

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C 1908

US Classification:

570129

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2 -trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

US Patent:

50119559, Apr 30, 1991

Filed:

Oct 10, 1989

Appl. No.:

7/419554

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

International Classification:

C07C 1516
C09B 1104
C09B 1106

US Classification:

552101

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.

US Patent:

49122380, Mar 27, 1990

Filed:

Dec 30, 1988

Appl. No.:

7/292049

Inventors:

William B. Alston - Medina OH
Roy F. Gratz - Fredericksburg VA

Assignee:

The United States of America as represented by the United States
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C 1516

US Classification:

552101

Abstract:

Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.