Abstract: A transition metal mediated chain transfer agent controlled polymerization process is described. The process combines the advantages of atom transfer radical polymerization (ATRP) and reversible addition fragmentation transfer (RAFT) polymerization. Synthesis of chain transfer agents useful in the disclosed processes is also disclosed. Other improvements on ATRP RAFT processes are also described.
Type:
Grant
Filed:
March 6, 2009
Date of Patent:
May 21, 2013
Assignee:
Carnegie Mellon University
Inventors:
Yungwan Kwak, Renaud Nicolay, Krzysztof Matyjaszewski
Abstract: A transition metal mediated chain transfer agent controlled polymerization process is described. The process combines the advantages of atom transfer radical polymerization (ATRP) and reversible addition fragmentation transfer (RAFT) polymerization. Synthesis of chain transfer agents useful in the disclosed processes is also disclosed. Other improvements on ATRP RAFT processes are also described.
Type:
Application
Filed:
March 6, 2009
Publication date:
February 24, 2011
Inventors:
Krzysztof Matyjaszewski, Yungwan Kwak, Renaud Nicolay
Abstract: Dithiocarbonate-containing macromer that contain biodegradable or water-soluble segments, and polymers derived from the reaction of these dithiocarbonate-containing macromers, are disclosed. The polymers derived from these dithiocarbonate-containing macromers with biodegradable or water-soluble segments are useful in medical and pharmaceutical applications.
Type:
Grant
Filed:
March 27, 2006
Date of Patent:
August 11, 2009
Assignee:
Ethicon, Inc. - USA
Inventors:
Ankur S. Kulshrestha, Kevin Cooper, Walter R. Laredo
Abstract: Dithiocarbonate derivatives are disclosed, along with a process for preparing the same. The dithiocarbonate compounds can be utilized as initators, chain transfer agents and/or terminators in controlled free radical polymerizations. The dithiocarbonates can be used to produce polymers having narrow molecular weight distribution. Advantageously, the compounds of the present invention can also introduce functional groups into the resulting polymers. The dithiocarbonate compounds have low odor and are substantially colorless.
Abstract: Thiocarbonate compounds which, in one embodiment, are utilized as a rheology modifier or associative thickener. The thiocarbonate compounds thicken or increase the viscosity of a composition, preferably an aqueous composition when used in an effective amount. In one preferred embodiment, the thiocarbonate compounds include at least one hydrophilic group containing repeat unit such as derived from acrylic acid, and at least one hydrophobic group to enhance association with other compounds and thus increase viscosity of a composition. Aqueous composition comprising a latex and thiocarbonate associative thickeners are described.
Abstract: Polymers and copolymers synthesized by means that yield a narrow range of molecular weights can have different properties than polymers synthesized by conventional means. In order to obtain such polymers, however, polymerization must be controlled. One type of controlled polymerization is the reversible addition-fragmentation chain transfer (RAFT) process, which has characteristics of a living polymerization. The present invention discloses a group of dithioesters and trithioesters suitable as chain transfer agents for RAFT polymerization. The present invention also discloses RAFT polymerizations conducted in aqueous media.
Type:
Grant
Filed:
January 29, 2007
Date of Patent:
July 22, 2008
Assignee:
University of Southern Mississippi
Inventors:
Charles L. McCormick, Michael S. Donovan, Andrew B. Lowe, Brent S. Sumerlin, David B. Thomas
Abstract: The current invention provide novel compounds, methods of treating or preventing emphysema, cancer and dermatological disorders, pharmaceutical compositions suitable for the treatment or prevention of emphysema, cancer and dermatological disorders and methods for delivering formulations into the lung of a mammal suffering from emphysema, cancer and dermatological disorders.
Type:
Application
Filed:
September 17, 2002
Publication date:
August 21, 2003
Applicant:
Roche Bioscience, a division of Syntex (U.S.A.) LLC
Inventors:
Paula Nanette Belloni, Denis John Kertesz, Michael Klaus, Jean-Marc Lapierre
Abstract: This invention relates to novel alkylxanthates of formulae 1 to 3 and use of alkylxanthates of formulae 1 to 6 in the integrated pest management, more specifically alkyl xanthates are used as insect growth regulators for pest management in agricultural fields no or less environmental impact.
Type:
Grant
Filed:
March 30, 2001
Date of Patent:
June 24, 2003
Assignee:
Council of Scientific & Industrial Research
Abstract: The invention relates to the use of 2-(3,4-dihydroxyphenyl)ethyl-substituted carbonic acid derivatives as antioxidants or free-radical scavengers, in particular to the use for protecting human cells and tissues from the harmful, aging-accelerating effects of free-radicals and reactive oxygen compounds.
Abstract: This invention relates to novel alkylxanthates of formulae 1 to 3 and use of alkylxanthates of formulae 1 to 6 in the integrated pest management, more specifically alkyl xanthates are used as insect growth regulatory for pest management in agricultural fields no or less environmental impact.
Type:
Application
Filed:
March 30, 2001
Publication date:
January 30, 2003
Applicant:
COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
Abstract: "Esters" are synthesized by reacting a nucleophile with a propargyl xanthate advantageously having the formula (I):R.sub.3 --C.tbd.C--CR.sub.1 R.sub.2 --S--CS--Y--R (I)in the presence of at least one acid, Bronsted or otherwise, and at a temperature ranging from 0.degree. to 300.degree. C.; the subject reaction is particularly applicable to a wide variety of chiral organic syntheses.
Type:
Grant
Filed:
March 18, 1997
Date of Patent:
November 2, 1999
Assignee:
Rhone-Poulenc Chimie
Inventors:
Jean Boivin, Eric B. Henriet, Samir Z. Zard
Abstract: Described herein are compounds of Formula (XX) and Formula (XXIV), shown below, and processes of making same. ##STR1## wherein p is 0 ##STR2## wherein p is 1, and Y is chlorine or bromine.
Type:
Grant
Filed:
November 12, 1996
Date of Patent:
July 7, 1998
Assignee:
Zeneca Limited
Inventors:
Ian Richard Matthews, Christopher Richard Ayles Godfrey, John Martin Clough
Abstract: "Esters" are synthesized by reacting a nucleophile with a propargyl xanthate advantageously having the formula (I):R.sub.3 --C.tbd.C--CR.sub.1 R.sub.2 --S--CS--Y--R (I)in the presence of at least one acid, Bronsted or otherwise, and at a temperature ranging from 0.degree. to 300.degree. C.; the subject reaction is particularly applicable to a wide variety of chiral organic syntheses.
Type:
Grant
Filed:
May 30, 1995
Date of Patent:
June 10, 1997
Assignee:
Rhone-Poulenc Chimie
Inventors:
Jean Boivin, Eric B. Henriet, Samir Z. Zard
Abstract: Oligomeric thiocarbonates such as hexathiodicarbonate salts and thioesters are used as pesticides and preservatives. Certain oligomeric thiocarbonate salts, notably quaternary ammonium hexathiodicarbonates, are prepared. The compounds are stabilized with added base and/or sulfide.
Abstract: Oligomeric thiocarbonates such as hexathiodicarbonate salts and thioesters are used as pesticides and preservatives. Certain oligomeric thiocarbonate salts, notably quaternary ammonium hexathiodicarbonates, are prepared. The compounds are stabilized with added base and/or sulfide.
Abstract: Alkyl xanthates of phenols are prepared by a method comprising contacting an alkali metal salt of a phenol that is substantially free of water with carbon disulfide and an alkylating agent while employing a solvent in the reaction mixture.
Abstract: A methylene bisxanthate chemical compound is produced by reaction of an aqueous solution of an alkaline xanthate with methylene chloride in the presence of a polyethylene glycol (PEG) with alcoholic terminal groups as a phase transfer catalyst. The PEG is water soluble and may be recovered and recycled in the process. The reaction product may be purified, but can be used in the crude state as a collector reagent in the froth flotation of sulfide minerals, or of sulfidized oxide minerals, from their ores.
Abstract: This invention relates to a method of recovering non-ferrous metal sulfides from a metal ore which comprises subjecting the metal ore, in the form of an aqueous pulp, to a froth flotation process in the presence of a flotating amount of a flotation collector wherein the collector comprises a compound which corresponds to one of the formulas ##STR1## wherein R.sup.1 is alkyl, aryl or aralkyl group wherein the aryl and aralkyl can be substituted with a halo or alkyl moiety;R.sup.2 is alkyl, aryl or aralkyl group wherein the aryl or aralkyl can be substituted with a halo or alkyl moiety;R.sup.3 is aryl or aralkyl unsubstituted or substituted with a halo or alkyl moiety;R.sup.4 is alkyl, aryl or aralkyl group wherein the aryl or aralkyl can be substituted with a halo or alkyl moiety; with the proviso that at least one of R.sup.1 and R.sup.2 must be aryl or aralkyl unsubstituted or substituted;under conditions such that the metal sulfide values are recovered in the froth.
Type:
Grant
Filed:
October 28, 1985
Date of Patent:
December 27, 1988
Assignee:
The Dow Chemical Company
Inventors:
Guy H. Harris, Patrice K. Ackerman, Frank F. Aplan