Patents by Inventor Paul M. Hergenrother

Paul M. Hergenrother 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: 7109287
    Abstract: Polyimides displaying low color in thin films, atomic oxygen resistance, vacuum ultraviolet radiation resistance, solubility in organic solvents in the imide form, high glass transition (Tg) temperatures, and high thermal stability are provided. The poly(amide acid)s, copoly(amide acid)s, polyimides and copolyimides are prepared by the reaction of stoichiometric ratios of an aromatic dianhydride with diamines which contain phenylphosphine oxide groups in polar aprotic solvents. Controlled molecular weight oligomeric (amide acid)s and imides can be prepared by offsetting the stoichiometry according to the Carothers equation using excess diamine and endcapping with aromatic anhydrides.
    Type: Grant
    Filed: November 8, 2004
    Date of Patent: September 19, 2006
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother, Kent A. Watson, Craig M. Thompson
  • Patent number: 6958192
    Abstract: The present invention relates generally to polyimides. It relates particularly to novel polyimides prepared from 2,3,3?,4?-biphenyltetracarboxylic dianhydride and aromatic diamines. These novel polyimides have low color, good solubility, high thermal emissivity, low solar absorptivity and high tensile strength.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: October 25, 2005
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Joseph G. Smith, Jr., John W. Connell, Kent A. Watson
  • Patent number: 6841652
    Abstract: Polyimides displaying low color in thin films, atomic oxygen resistance, vacuum ultraviolet radiation resistance, solubility in organic solvents in the imide form, high glass transition (Tg) temperatures, and high thermal stability are provided. The poly(amide acid)s, copoly(amide acid)s, polyimides and copolyimides are prepared by the reaction of stoichiometric ratios of an aromatic dianhydride with diamines which contain phenylphosphine oxide groups in polar aprotic solvents.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: January 11, 2005
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother, Kent A. Watson, Craig M. Thompson
  • Publication number: 20030212243
    Abstract: The present invention relates generally to polyimides. It relates particularly to novel polyimides prepared from 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines. These novel polyimides have low color, good solubility, high thermal emissivity, low solar absorptivity and high tensile strength.
    Type: Application
    Filed: April 7, 2003
    Publication date: November 13, 2003
    Applicant: Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Joseph G. Smith, John W. Connell, Kent A. Watson
  • Publication number: 20030158351
    Abstract: Phenylethynyl containing imide-silanes were prepared from aminoalkyl and aminoaryl alkoxy silanes and 4-phenyletbynylphthalic anhydride in toluene to form the imide in one step or in N-methyl-2-pyrrolidinone (NMP) to form the amide acid intermediate. Controlled molecular weight pendent phenylethynyl amide acid oligomers terminated with aminoaryl alkoxy silanes were prepared in NMP from aromatic dianhydrides, aromatic diamines, diamines containing pendent phenylethynyl groups and aminoaryl alkoxy silanes. The phenylethynyl containing imide-silanes and controlled molecular weight pendent phenylethynyl amide acid oligomers terminated with aminoaryl alkoxy silanes were used to improve the adhesion between phenylethynyl containing imide adhesives and inorganic substrates (i.e. metal). Hydrolysis of the alkoxy silane moiety formed a silanol functionality which reacted with the metal surface to form a metal-oxygen-silicon (oxane) bond under the appropriate reaction conditions.
    Type: Application
    Filed: June 12, 2002
    Publication date: August 21, 2003
    Inventors: Joseph G. Smith, John W. Connell, Paul M. Hergenrother, Sharon E. Lowther, Cheol Park
  • Publication number: 20030045670
    Abstract: Polyimides displaying low color in thin films, atomic oxygen resistance, vacuum ultraviolet radiation resistance, solubility in organic solvents in the imide form, high glass transistion (Tg) temperatures, and high thermal stability are provided. The poly(amide acid)s, copoly(amide acid)s, polyimides and copolyimides are prepared by the reaction of stoichiometric ratios of an aromatic dianhydride with diamines which contain phenylphosphine oxide groups in polar aprotic solvents.
    Type: Application
    Filed: March 8, 2002
    Publication date: March 6, 2003
    Inventors: John W. Connell, Joseph G. Smith, Paul M. Hergenrother, Kent A. Watson, Craig M. Thompson
  • Patent number: 6441099
    Abstract: Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: August 27, 2002
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Adminstration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
  • Patent number: 6359107
    Abstract: A composition of and method for making high performance imide resins that are processable by resin transfer molding (RTM) and resin infusion (RI) techniques were developed. Materials with a combination of properties, making them particularly useful for the fabrication of composite parts via RTM and/or RI processes, were prepared, characterized and fabricated into moldings and carbon fiber reinforced composites and their mechanical properties were determined. These materials are particularly useful for the fabrication of structural composite components for aerospace applications. The method for making high performance resins for RTM and RI processes is a multi-faceted approach. It involves the preparation of a mixture of products from a combination of aromatic diamines and aromatic dianhydrides at relatively low calculated molecular weights (i.e. high stoichiometric offsets) and endcapping with latent reactive groups.
    Type: Grant
    Filed: May 18, 2000
    Date of Patent: March 19, 2002
    Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Paul M. Hergenrother
  • Patent number: 6350817
    Abstract: Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: February 26, 2002
    Assignee: The United States of America as represented by the United States National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
  • Patent number: 6124035
    Abstract: High temperature resins containing phenylethynyl groups that are processable by transfer molding have been prepared. These phenylethynyl containing oligomers were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynlphthalic anhydride in glacial acetic acid to form a mixture of imide compounds in one step. This synthetic approach is advantageous since the products are a mixture of compounds and consequently exhibit a relatively low melting temperature. In addition, these materials exhibit low melt viscosities which are stable for several hours at 210-275.degree. C., and since the thermal reaction of the phenylethynyl group does not occur to any appreciable extent at temperatures below 300.degree. C., these materials have a broad processing window. Upon thermal cure at .about.300-350.degree. C., the phenylethynyl groups react to provide a crosslinked resin system.
    Type: Grant
    Filed: April 13, 1999
    Date of Patent: September 26, 2000
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
  • Patent number: 5760168
    Abstract: Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: June 2, 1998
    Assignee: The United States of America as represented by the Administrator of the National Aeuonautics and Space Administration
    Inventors: Paul M. Hergenrother, Joesph G. Smith, Jr.
  • Patent number: 5689004
    Abstract: Controlled molecular weight imide oligomers and co-oligomers containing pendent phenylethynyl groups (PEPIs) and endcapped with nonreactive or phenylethynyl groups have been prepared by the cyclodehydration of the precursor amide acid oligomers or co-oligomers containing pendent phenylethynyl groups and endcapped with nonreactive or phenylethynyl groups. The amine terminated amide acid oligomers or co-oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and diamine containing pendent phenylethynyl groups and subsequently endcapped with a phenylethynyl phthalic anhydride or monofunctional anhydride. The anhydride terminated amide acid oligomers and co-oligomers are prepared from the reaction of diamine(s) and diamine containing pendent phenylethynyl group(s) with an excess of dianhydride(s) and subsequently endcapped with a phenylethynyl amine or monofunctional amine.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: November 18, 1997
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
  • Patent number: 5681967
    Abstract: Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: October 28, 1997
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Joseph G. Smith, Jr.
  • Patent number: 5637670
    Abstract: Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: June 10, 1997
    Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space Administration
    Inventors: John W. Connell, Paul M. Hergenrother, Joseph G. Smith, Jr.
  • Patent number: 5606014
    Abstract: Controlled molecular weight imide oligomers and co-oligomers containing pendent phenylethynyl groups (PEPIs) and endcapped with nonreactive or phenylethynyl groups have been prepared by the cyclodehydration of the precursor amide acid oligomers or co-oligomers containing pendent phenylethynyl groups and endcapped with nonreactive or phenylethynyl groups. The amine terminated amide acid oligomers or co-oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and diamine containing pendent phenylethynyl groups and subsequently endcapped with a phenylethynyl phthalic anhydride or monofunctional anhydride. The anhydride terminated amide acid oligomers and co-oligomers are prepared from the reaction of diamine(s) and diamine containing pendent phenylethynyl group(s) with an excess of dianhydride(s) and subsequently endcapped with a phenylethynyl amine or monofunctional amine. The polymerizations are carried out in polar aprotic solvents such as under nitrogen at room temperature.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: February 25, 1997
    Assignee: The United States of America as represented by the United States National Aeronautics and Space Administration
    Inventors: John W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
  • Patent number: 5599993
    Abstract: Four phenylethynyl amine compounds--3 and 4-aminophenoxy-4'-phenylethynylbenzophenone, and 3 and 4-amino-4'-phenylethynylbenzophenone--were readily prepared and were used to endcap imide oligomers. Phenylethynyl-terminated amide acid oligomers and phenylethynyl-terminated imide oligomers with various molecular weights and compositions were prepared and characterized. These oligomers were cured at 300.degree. C. to 400.degree. C. to provide crosslinked polyimides with excellent solvent resistance, high strength and modulus and good high temperature properties. Adhesive panels, composites, films and moldings from these phenylethynyl terminated imide oligomers gave excellent mechanical performance.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: February 4, 1997
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Robert G. Bryant, Brian J. Jensen, Stephen J. Havens
  • Patent number: 5567800
    Abstract: Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: October 22, 1996
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Joseph G. Smith, Jr.
  • Patent number: 5554715
    Abstract: Novel poly(N-arylenebenzimidazole)s (PNABls) are prepared by the aromatic nucleophilic displacement reaction of novel di(hydroxyphenyl-N-arylene benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl-N-arylenebenzimidazole) monomers are synthesized by reacting phenyl-4-hydroxybenzoate with bis(2-aminoanilino)arylenes in diphenylsulfone. Moderate molecular weight PNABIs of new chemical structures were prepared that exhibit a favorable combination of physical and mechanical properties. The use of the novel di(hydroxyphenyI-N-arylenebenzimidazole)s permits a more economical and easier way to prepare PNABIs than previous routes.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: September 10, 1996
    Assignee: The United States of America as represented by the Administrator of National Aeronautics and Space Administration
    Inventors: John W. Connell, Paul M. Hergenrother, Joseph G. Smith, Jr.
  • Patent number: 5498803
    Abstract: Poly(arylene ether)s containing pendent ethynyl and substituted ethynyl groups and poly(arylene ether) copolymers containing pendent ethynyl and substituted ethynyl groups are readily prepared from bisphenols containing ethynyl and substituted ethynyl groups. The resulting polymers are cured up to 350.degree. C. to provide crosslinked poly(arylene ether)s with good solvent resistance, high strength and modulus.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: March 12, 1996
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, Brian J. Jensen
  • Patent number: 5446204
    Abstract: A composition of matter having the general structure: ##STR1## (wherein X is F, Cl, or NO.sub.2, and Y is CO, SO.sub.2 or C(CF.sub.3).sub.2) is employed to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent having the general structure: ##STR2## (wherein R is any aliphatic or aromatic moiety) is employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react therewith to provide a thermosetting material of enhanced density. These materials have features which make them attractive candidates for use as composite matrices and adhesives.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: August 29, 1995
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert G. Bryant, Brian J. Jensen, Paul M. Hergenrother