Patents by Inventor Ramone Givens

Ramone Givens 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).

  • Synthesis of polycarbonates using Co2
    Patent number: 6288202
    Abstract: A process of forming a polycarbonate comprises providing a reaction mixture of at least one polycarbonate-forming monomer and carbon dioxide; and then reacting the polycarbonate-forming monomer and carbon dioxide in the reaction mixture to form the polycarbonate. In one embodiment, the polycarbonate is present in a condensate, and the process further comprises removing carbon dioxide from the reaction mixture; and then collecting the condensate from the reaction mixture. Moreover, uncrystallized polycarbonate may be treated with carbon dioxide to form crystalline polycarbonate. The crystalline polycarbonate is then rendered useful for solid state polymerization.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: September 11, 2001
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Joseph M. DeSimone, Ramone Givens, Mitsutoshi Jikei, Jeffrey D. Cohen
  • Synthesis of polyamides in liquid and supercritical CO.sub.2
    Patent number: 6025459
    Abstract: A method of forming a polyamide from a corresponding nylon salt material comprises providing a reaction mixture comprising a nylon salt and carbon dioxide; and then condensing the nylon salt in the carbon dioxide to form a polyamide and water. A method of forming a polyamide comprises providing a reaction mixture containing at least one lactam monomer and carbon dioxide; and then polymerizing the lactam monomer in the carbon dioxide to form a polyamide.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: February 15, 2000
    Assignee: The University of North Carolina at Chapel Hill
    Inventors: Joseph DeSimone, Ramone Givens, Yizeng Ni