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

Robert C Evers

My Dotrong

George J Moore

Tonson Abraham

Edward J Soloski

Minhhoa Dotrong

Fred E Arnold, Jr

Thuy D Dang

Thaddeus E Helminiak

Mark Sinsky

Ronald C Tomlinson

D Roger Moore

High compressive strength, three-dimensional para-oriented benzobisoxazole polymers of the formula: ##STR1## wherein Q is ##STR2## and wherein Z represents repeating units of the formula: ##STR3##

Adamantane based three-dimensional rigid-rod polymers

A two-dimensional, rigid-rod polymer of the formula: ##STR1## wherein x, y and z each has a value of 5 to 40; wherein the sum of x, y and z is about 20 to 100; and wherein PBX is a repeating group of the formula: ##STR2## is prepared by the polycondensation of trimeric acid (TMA) ##STR3## with 4-[5-amino-6-hydroxybenzoxazol-2-yl]benzoic acid (ABA) ##STR4## in polyphosphoric acid (PPA).

Two-dimensional benzobisoxazole rigid-rod polymers

There are provided fusible, rod-like graft copolymers having repeating units of the formula: ##STR1## wherein a ranges from about 0.75 to 0.97 and b is 1-a; wherein Z is a benzbisoxazole or benzbisthiazole moiety, wherein Ar is a linear phenylene or polyphenylene moiety, wherein Ar' is ##STR2## and wherein Y is a poly(etherketone) or a poly(etheretherketone), wherein the poly(etherketone) has repeating units of the formula ##STR3## wherein Q is a divalent phenylene or substituted phenylene moiety and c is an integer having a value of 1 to 4, and the poly(etheretherketone) has repeating units of the formula ##STR4## wherein Q' is a divalent phenylene or substituted phenylene moiety, d is an integer having a value of 1 to 4 and e is an integer having a value of 2 to 5. Also provided are methods for making these graft copolymers.

Graft copolymers of articulated rod-like polymers

Benzobisthiazole polymers with thiophene moieties having repeating units of the formula:

Benzobisthiazole polymers with thiophene moieties

Fusible, rod-like, graft polymers and copolymers having repeating units of the formula: ##STR1## wherein x ranges from 0 to about 0.97, y is 1-x, Y is a poly(etherketone) (PEK) or a poly(etheretherketone) (PEEK), and wherein Ba is a benzobisimidazole or benzobisthiazole moiety are provided. Also provided are methods for preparing the above polymers and copolymers, 2-(2,6-dimethylphenoxy)terephthalic acid and a method for preparing the latter.

Rigid-rod graft polymers and copolymers

There is provided a para-ordered, rigid-rod aromatic heterocyclic copolymer having repeating groups of the formula:

Crosslinkable rigid-rod aromatic heterocyclic polymer

A fusible, rod-like, graft copolymer having repeating units of the formula: ##STR1## wherein X is (--CH.sub.2 CH.sub.2 CONH--).sub.m or (--CH.sub.2 --CH(CH.sub.3)--O--).sub.n, wherein m has an average value of 5.0 to 35.0 and n has an average value of 1.0 to 30.0.

Graft copolymers of poly(p-phenylene benzbisimidazole)

There is provided an aromatic polyamide having repeating units of the formula: ##STR1## wherein X is -O-, -S-, -CO- or -SO.sub.2 - and y has a value of 1 or 2. Also provided is an aromatic polyamide having repeating units of the formula: ##STR2## and a new composition of matter 3-[4-(3-aminophenoxy benzoyl)phenoxy] benzoic acid.

Low glass transition temperature aromatic polyamide

Provided is an acetylene-terminated aromatic amide compound of the formula ##STR1## wherein X is --O-- or --S--, Z is --O--, --S--, --SO.sub.2 --, or --CO--, and R is --H or --C.tbd.CH in the ortho, meta or para position, wherein at least one R is --.tbd.CH.

Acetylene terminated aromatic amide monomers

Aromatic polyamide resins having repeating units, each containing at least one m-ethynyl amido subunit: ##STR1## These resins can be thermally treated to undergo intra-molecular cyclization, without evolution of volatiles, into polyimidines containing the following subunit. ##STR2##

Ethynyl-containing aromatic polyamide resin

Aromatic monomers, each containing at least one o-ethynyl carboxylic acid halide subunit: ##STR1## wherein X is Cl or Br. These monomers can be reacted with amines to form aromatic polyamide resins which can be thermally treated to undergo intromolecular cyclization, without evolution of volatiles, into polyimidines.

Ethynyl-containing phthaloyl halides

Articulated p-benzobisoxazole and p-benzobisthiazole polymers which contain a limited number of 3,3'-biphenyl or 2,2'-bipyridyl segments are synthesized, with inherent viscosities as high as 14 dl/g being recorded. The 3,3'-biphenyl or 2,2'-bipyridyl segments in the p-benzobisoxazole and p-benzobisthiazole polymers impart flexibility to the polymers without adversely affecting the thermooxidative stability. While the resultant articulated polymers exhibit liquid crystalline behavior in methanesulfonic acid and form strong cast films from that solvent, they also exhibit thermooxidative stability comparable to other p-benzobisthiazole and p-benzobisoxazole polymers. The resultant films are useful for the fabrication of high strength laminates to be used in severe environment structural applications.

Thermooxidatively stable articulated p-benzobisoxazole and

Para-ordered aromatic heterocyclic polymers characterized by having p-benzbisoxazole, p-benzbisthiozole or p-benzbisimidazole units and containing diphenoxybenzene structures. The diphenoxybenzene structures function as 'swivels' in the polymer chains, imparting flexibility thereto and making it possible to cast strong films from solutions of the polymers.

Articulated para-ordered aromatic heterocyclic polymers containing

2-Amino-4-ethynylphenol, a novel compound, is prepared by a four-step synthetic sequence in which the key reaction is the treatment of 4-acetoxy-3-nitroacetophenone with a Vilsmeier reagent derived from N,N-dimethylformamide and phosphorus oxychloride. The compound is useful as an endcapping agent in the synthesis of fluorocarbon ether bibenzoxazole oligomers which, because of the presence of acetylenic terminal groups, can be cured by thermal means to provide broad-use temperature, fuel and fluid resistant vulcanizates.

Growing community of inventors

Dayton, OH, United States of America

Robert C Evers