Patents by Inventor Maria Spinu

Maria Spinu 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).

  • Publication number: 20060157882
    Abstract: This invention relates to ultramicrocellular structures that incorporate fillers such as functional fillers.
    Type: Application
    Filed: December 7, 2005
    Publication date: July 20, 2006
    Inventors: Simona Percec, Maria Spinu
  • Publication number: 20060159907
    Abstract: This invention relates to ultramicrocellular structures that incorporate fillers such as functional fillers.
    Type: Application
    Filed: December 7, 2005
    Publication date: July 20, 2006
    Inventors: Simona Percec, Maria Spinu, Irene Plotzker
  • Patent number: 6921795
    Abstract: Blends of two or more polyethylenes are made by reacting ethylene with an oligomerization catalyst that forms ?-olefins, and two polymerization catalysts, one of which under the process conditions copolymerizes ethylene and ?-olefins, and the other of which under process conditions does not readily copolymerize ethylene and ?-olefins. The blends may have improved physical properties and/or processing characteristics.
    Type: Grant
    Filed: February 6, 2003
    Date of Patent: July 26, 2005
    Assignee: E.I. du Pont de Nemours and Company
    Inventors: Lin Wang, Maria Spinu, Joel David Citron
  • Publication number: 20040048989
    Abstract: Blends of two or more polyethylenes are made by reacting ethylene with an oligomerization catalyst that forms &agr;-olefins, and two polymerization catalysts, one of which under the process conditions copolymerizes ethylene and &agr;-olefins, and the other of which under process conditions does not readily copolymerize ethylene and &agr;-olefins. The blends may have improved physical properties and/or processing characteristics.
    Type: Application
    Filed: September 10, 2003
    Publication date: March 11, 2004
    Inventors: Lin Wang, Maria Spinu, Joel David Citron
  • Publication number: 20030149182
    Abstract: Blends of two or more polyethylenes are made by reacting ethylene with an oligomerization catalyst that forms &agr;-olefins, and two polymerization catalysts, one of which under the process conditions copolymerizes ethylene and &agr;-olefins, and the other of which under process conditions does not readily copolymerize ethylene and &agr;-olefins. The blends may have improved physical properties and/or processing characteristics.
    Type: Application
    Filed: February 6, 2003
    Publication date: August 7, 2003
    Inventors: Lin Wang, Maria Spinu, Joel David Citron
  • Patent number: 6555631
    Abstract: Blends of two or more polyethylenes are made by reacting ethylene with an oligomerization catalyst that forms &agr;-olefins, and two polymerization catalysts, one of which under the process conditions copolymerizes ethylene and &agr;-olefins, and the other of which under process conditions does not readily copolymerize ethylene and &agr;-olefins. The blends may have improved physical properties and/or processing characteristics.
    Type: Grant
    Filed: September 28, 2000
    Date of Patent: April 29, 2003
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Lin Wang, Maria Spinu, Joel David Citron
  • Patent number: 6297330
    Abstract: This invention concerns a process for polymerizing cyclic oligomers to homopolymers or copolymers, conducted in the presence of one or more linear polymers.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: October 2, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Robert Ray Burch, Jr., Alexa Ann Dembek, Steven Raymond Lustig, Maria Spinu
  • Patent number: 5346966
    Abstract: Linear stereo block copolymers are disclosed. The polymers comprise a plurality of alternating polymeric blocks of amorphous copolymers of L-lactide and D-lactide with semicrystalline blocks of either L-lactide homopolymer or D-lactide homopolymer. The molecular weight can be built up by either of two techniques. The first technique is to use a chain extending agent such as a diacyl chloride or a diisocyanate to link a plurality of the preformed block copolymers. The second technique is to polymerize additional alternating amorphous and semicrystalline segments or blocks onto the original alternating block copolymers.
    Type: Grant
    Filed: October 26, 1993
    Date of Patent: September 13, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Maria Spinu
  • Patent number: 5331045
    Abstract: Polyvinyl alcohol esterified by lactic is produced by dissolving polyvinyl alcohol and lactic acid in water, and removing the water by volatilization at a temperature of 75.degree. C. to 175.degree. C. The lactic acid esterified polyvinyl alcohol is useful as a molding resin, and in films, fibers and adhesives.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: July 19, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Maria Spinu
  • Patent number: 5317064
    Abstract: Polylactide stereocomplex is formed by mixing poly-D-lactide and L-lactide or poly-L-lactide and D-lactide and a lactide polymerization catalyst, and heating to polymerize the monomeric lactide, preferably under pressure. The parts are useful in medical devices such as bone screws.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: May 31, 1994
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Maria Spinu
  • Patent number: 5270400
    Abstract: Linear block copolymers are disclosed. The polymers comprise a plurality of alternating polymeric blocks of amorphous copolymers of L-lactide and D-lactide with semicrystalline blocks of either L-lactide homopolymer or D-lactide homopolymer. The molecular weight can be built up by either of two techniques. The first technique is to use a chain extending agent such as a diacyl chloride or a diisocyanate to link a plurality of the preformed block copolymers. The second technique is to polymerize additional alternating amorphous and semicrystalline onto the original alternating block copolymers.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: December 14, 1993
    Inventor: Maria Spinu
  • Patent number: 5225521
    Abstract: Star-shaped poly (hydroxyacid) chains and the process for preparing them are disclosed. The star shaped polymers have the residue of a central polyfunctional compound having at least 5 hydroxyl or amino groups and 5 to 100 carbon atoms with polymeric arms attached to the functional groups. The polymeric arms are formed from lactide, glycolide or caprolactone. In a preferred aspect the inner segment of the arms are an amorphous copolymer of D-lactide and L-lactide and the outer segment of the arms are a semicrystalline polymer of one of L-lactide or D-lactide.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: July 6, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Maria Spinu
  • Patent number: 5210108
    Abstract: Environmentally benign closed cell compositions made by foaming star-shaped polymers with a plurality of poly(hydroxy acid) chains attached to a central polyfunctional compound having a plurality of hydroxyl and/or amino groups.
    Type: Grant
    Filed: July 29, 1992
    Date of Patent: May 11, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Maria Spinu, Thomas M. Ford
  • Patent number: 5202413
    Abstract: Polymers of the general formula R--(A-B-A-I)-.sub.x A-B-A-R and their preparation are disclosed. In the general formula, -A- is a polyhydroxy acid residue preferably a polymer of either 98 to 100% L-lactide or 98 to 100% D-lactide having a molecular weight of 500 to 40,000 and preferably 2,000 to 20,000, -B- is an oligomeric diol or diamine residue, having a number average molecular weight of 500 to 20,000 and preferably 2,000 to 8,000. The polymers are prepared by polymerizing a lactone onto the diol or diamine followed by reacting the resulting polymeric H-A-B-A-H with an diisocyanate or diacyl chloride to form the -L- chain extending units in the general formula.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: April 13, 1993
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Maria Spinu