Patents by Inventor Loon-Seng Tan

Loon-Seng Tan 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: 6743889
    Abstract: Novel ether-ketone hyperbranched co-polymers are prepared by co-polymerizing 3,5-bis(4-fluorobenzoyl)phenol and 4-fluoro-4′-hydroxybenzophenone. The resulting copolymer has repeating units of the formula: wherein n has a value of 0.25 to 0.99.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: June 1, 2004
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Jong-Beom Baek
  • Patent number: 6730793
    Abstract: Provided are chromophores of the formula Q—(—L—Z)x, wherein x is 2 or 3, wherein Q is selected from the group consisting of wherein L is wherein R is an alkyl group having 1 to 20 carbon atoms, and wherein Z is selected from the group consisting of
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: May 4, 2004
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Ramamurthi Kannan, Loon-Seng Tan, Bruce A. Reinhardt, Richard A. Vaia
  • Patent number: 6642347
    Abstract: Amine-terminated hyperbranched quinoxaline-amide polymers having repeating units of the formula: are useful to initiate bismaleimide polymerization and to increase the toughness of thermosets such as BMI and epoxies.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: November 4, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Jong-Beom Baek, Loon-Seng Tan, John B. Ferguson
  • Patent number: 6639042
    Abstract: New hyperbranched polymers having repeating units of the formula The polymer is prepared by the polymerization of the AB2 monomer N-{3,5-bis(4-hydroxybenzoyl)benzene}-4-fluoroisophthalimide.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: October 28, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Jong-Beom Baek, Loon-Seng Tan
  • Patent number: 6617462
    Abstract: Electropolymerizable monomers of the formulas wherein R1, R2 and R3 are selected from the group consisting of —H, —O(CH2)nCH3, wherein n has a value of 0 to 11 and m has a value of 1 to 4, and wherein no more than one of R2 and R3 is —H. Also provided are polymers resulting from the electropolymerization of these monomers.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: September 9, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Balasubramanian Sankaran
  • Patent number: 6608171
    Abstract: A hyperbranched polymer having repeating units of the formula: wherein Q is —O—, —S— or —NH—.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: August 19, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Jong-Beom Baek
  • Patent number: 6555682
    Abstract: Provided are chromophores of the formula Q—(—L—Z)x, wherein x is 3 or 4, wherein Q is selected from the group consisting of wherein L is selected from the group consisting of wherein R is an alkyl group having 1 to 20 carbon atoms, and wherein Z is selected from the group consisting of
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: April 29, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Ramamurthi Kannan, Loon-Seng Tan, Richard A. Vaia
  • Patent number: 6552195
    Abstract: AB2 monomers of the formula wherein Q is Polymerization of these monomers results in hyperbranched aromatic polyamides.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: April 22, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Jong-Beom Baek, Loon-Seng Tan
  • Patent number: 6541633
    Abstract: An AB2 monomer of the formula: wherein Z is selected from the group consisting of —OH, —SH and —NH2HCl, is useful for the preparation of hyperbranched polybenzoxazoles.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: April 1, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Jong-Beom Baek
  • Patent number: 6512124
    Abstract: A self-polymerizable AB2 monomer of the formula The resulting AB2 monomer can be polymerized to afford high molecular, low viscosity hyperbranched ether-ketone-imide polymer having repeating units with hydroxyl endgroups.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: January 28, 2003
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Jong-Beom Baek, Loon-Seng Tan
  • Patent number: 6359149
    Abstract: Provided are novel, electropolymerizable monomers of the formulae: wherein R1,R2 and R3 are selected from the group consisting of —H, —O(CH2)nCH3, wherein n has a value of 0 to 11 and m has a value of 1 to 4, and wherein no more than one of R2 and R3 is —H. Also provided are polymers resulting from the electropolymerization of these monomers.
    Type: Grant
    Filed: February 2, 2000
    Date of Patent: March 19, 2002
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Balasubramanian Sankaran
  • Patent number: 6355765
    Abstract: A wholly aromatic copolyester having repeating units of the formula: wherein Ar1 is wherein Q is selected from the group consisting of —H, —CH3, —CF3, —Cl, —Br, and —C6H5; wherein Ar2 is selected from the group consisting of wherein X is selected from the group consisting of —Br, —Cl, —CH3 and —C6H5; wherein Ar3 is wherein Ar4 is selected from the group consisting of wherein m has a value of 0.05 to 0.95 and n has a value of 100-m, is characterized by accessible nematic-isotropic transition temperatures providing outstanding orientational order and mechanical properties.
    Type: Grant
    Filed: September 25, 2000
    Date of Patent: March 12, 2002
    Assignee: United States of America as represented by the Secretary of the Air Force
    Inventors: Patrick T. Mather, Devdatt S. Nagvekar, Hong G. Jeon, Loon-Seng Tan
  • Patent number: 6300502
    Abstract: Provided are chromophores with very large two-photon absorption cross-sections. One group of these chromophores has the formula: (T—Q)n—N—Phm wherein Q is a single bond or 1,4-phenylene, Ph is a phenyl group, n has a value of 1-3 and m has a value of 3−n, and wherein T is wherein R1 and R2 are alkyl groups having 1 to 20 carbon atoms, provided that when Q is a single bond, the value of n is 2 or 3. Another group of these chromophores has the formula: (T—Q)n—G—Phm wherein T is as defined above, Q is a single bond or 1,4-phenylene, Ph is a phenyl group, n has a value of 1-4 and m has a value of 4−n, and wherein G is a 4-arm core unit. Yet another group of these chromophores has the formula: (T—Q)n—G—Phm wherein T is as described previously, Q is a single bond or 1,4-phenylene, Ph is a phenyl group, n has a value of 1-6 and m has a value of 6−n, and wherein G is a 6-arm core unit.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: October 9, 2001
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Ramamurthi Kannan, Bruce A. Reinhardt, Loon-Seng Tan
  • Patent number: 6291621
    Abstract: Provided are novel, electropolymerizable monomers of the formulae: wherein R1, R2 and R3 are selected from the group consisting of —H, —O(CH2)nCH3, wherein n has a value of 0 to 11 and m has a value of 1 to 4, and wherein no more than one of R2 and R3 is —H. Also provided are polymers resulting from the electropolymerization of these monomers.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: September 18, 2001
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Balasubramanian Sankaran
  • Patent number: 6197921
    Abstract: Provided are polymers prepared by the polymerization of monomers of the formulae:
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: March 6, 2001
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Balasubramanian Sankaran, Devdatt S. Nagvekar
  • Patent number: 6130339
    Abstract: Provided are novel, electropolymerizable monomers of the formulae: ##STR1##
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: October 10, 2000
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Devdatt S. Nagvekar, Balasubramanian Sankaran
  • Patent number: 6114498
    Abstract: An at least semiconductive polymer film is provided by infiltrating novel rigid-rod heterocyclic polymer film containing a 2,2'-bipyridine-5,5'-diyl moiety, with a conductive metal salt. These polymers have repeating units of the formula ##STR1## wherein Z is selected from the group consisting of ##STR2## wherein Q is --H or --C.sub.6 H.sub.5. Alternatively, the metal salt in the semiconductive polymer film can be reduced.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: September 5, 2000
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Jerald L. Burkett
  • Patent number: 5863658
    Abstract: A conductive composite composition consisting essentially of about 10 to 90 parts of the conducting form of polyaniline, balance an aromatic benzobisthiazole, benzobisoxazole or benzobisimidazole rigid-rod polymer, and a process for making a conductive benzobisazole polymer film.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: January 26, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Loon-Seng Tan
  • Patent number: 5670651
    Abstract: Benzocyclobutene-terminated monomers of the formula ##STR1## wherein Ar is --SO.sub.2 --, --CO--, or ##STR2## are prepared by reacting a benzocyclobutene of the formula ##STR3## wherein R is --H or --SiMe.sub.3, with a difluorophenyl compound of the formula ##STR4## wherein Ar is as described previously, in the presence of a promoter. A mixture of the resins is obtained when potassium carbonate is employed as the promoter. The bis(benzocyclobutene)-terminated monomer is obtained when cesium fluoride is employed as the promoter.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: September 23, 1997
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Loon-Seng Tan, Narayanan Venkatasubramanian
  • Patent number: 5663437
    Abstract: A new benzidine monomer composition containing an asymmetrically situated benzamide (iminobenzoyl) group: ##STR1## was prepared from the benzolyation reaction of 4,4'-dinitro-2-biphenylamine and benzoyl chloride, followed by catalytic hydrogenation. The compound can be used as a comonomer in the preparation of soluble thermoplastic polyamides, polyimides and other high performance polymers whose preparations require a diamine monomer.
    Type: Grant
    Filed: February 2, 1996
    Date of Patent: September 2, 1997
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Loon-Seng Tan