 Hot melt adhesive |
| What is claimed is: 1. A hot melt adhesive composition for bonding polypropylene substrates, said ... |
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| Flame retardant compositions |
| What is claimed is: 1. The flame retardant polymer composition comprising a linear alternating ... |
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| Oil resistant thermoplastic elastomer |
| The thermoplastic elastomer compositions produced according to the process of the present ... |
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| Catalysts for the polymerization of olefins |
| We claim: 1. A catalyst-forming component for use in preparing catalysts for the polymerization of ... |
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| Catalyst for polymerizing an olefin and method for producing an olefin polymer |
| We claim: 1. A catalyst for polymerizing an olefin which consists essentially of a product obtained ... |
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| Process for preparing biaxially oriented polypropylene film suitable for twist wrapping |
| It is therefore an object of the instant invention to provide a multilayered, coextruded, highly ... |
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| Process for the production of a biaxially highly oriented polypropylene film |
| The propylene polymer of the base ply (or single ply, if there are no top plies) is preferably ... |
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| Process for making a drag shield for a power mower |
| With the problems of the prior art in mind, the present invention includes two opposing and spaced ... |
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Process for producing telechelic, branched and star thermoplastic resin polymers
| Details |
Inventors: Moffat, Karen A.; Kazmaier, Peter M.; Hamer, Gordon K.; Georges, Michael K.;
Assignee: Xerox Corporation (Stamford, CT)
Primary Examiner: Nagumo; Mark
Assistant Examiner:
Attorney, Agent or Firm: Oliff & Berridge
A free radical polymerization process for the preparation of a thermoplastic resin or resins includes heating a mixture of a multifunctional nitroxide compound and at least one polymerizable monomer compound to form a thermoplastic resin or resins; cooling the mixture; and optionally isolating and washing and drying the thermoplastic resin. A multifunctional nitroxide compound for use in the reaction is formed from a stable free radical agent and a compound having one or more halide functional groups. The free radical polymerization process may be used to prepare telechelic, branched and star polymers. |
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The free radical polymerization process of the present invention may be used to prepare a variety of telechelic, branched and star polymers and copolymers with a variety of molecular architectures in a cost efficient manner.
An advantage of the present invention is that the stable free radical polymerization process affords precise control over the molecular architecture of the polymer, including molecular weight, molecular weight distribution and modality.
The polymers may generally be produced by the two-step process of: (a) generating a multifunctional nitroxide compound by reacting a nitroxide stable free radical agent with an alkyl or aryl halide or .
alpha.
-keto halide reagent having reactive halide functional groups, in the presence of a hydride generating compound; and (b) using the multifunctional nitroxide compound to polymerize one or more monomers by a stable free radical polymerization process.
In embodiments, it may be possible to increase the efficiency of the polymerization process of the present invention by both generating the multifunctional nitroxide compound and polymerizing the monomer or monomers in the same reaction vessel, without first isolating the multifunctional nitroxide compound.
These processes may, for example, be used to produce thermoplastic resins, including telechelic, branched and star polymer and block copolymer resins, having a number average molecular weight in the range of from about 1,000 to about 1,000,000.
Stable free radical agents are known in the literature.
For example G.
Moad et al.
, Tetrahedron Letters, 22, 1165 (1981), which is totally incorporated herein by reference, discloses stable free radical agents as free radical polymerization inhibitors.
However, under the free radical polymerization conditions of the present invention, stable free radical agents function as moderators to harness the normally highly reactive and indiscriminate intermediate free radical species.
Stable free radical agents as reaction moderators are disclosed in U
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Adhesives and Rubbers 
