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US 5,677,388 AGranted
Difunctional living free radical polymerization initiators
AssigneeThe Dow Chemical Company
InventorsRobert A. Koster, Duane B. Priddy, Irene Li
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Abstract
A living free-radical polymerization process for preparing polymers from vinyl aromatic monomers comprising polymerizing the vinyl aromatic monomer in the presence of a difunctional nitroxyl initiator.
Claims7
A process for preparing a triblock copolymer comprising:
- a) polymerizing a monomer (B) capable of free radical polymerization in the presence of:
- 1) a dinitroxyl azo, dinitroxyl disulfide or dinitroxyl peroxide initiator, or
- 2) any azo, disulfide or peroxide initiator and a dinitroxyl addition fragmentation chain transfer agent,
- at a temperature below the nitroxyl activation temperature to produce a telechelic polymer macroinitiator having nitroxyl functionalized chain-ends;
- b) contacting the polymer produced in a) with at least one additional monomer (A) at a temperature above the nitroxyl activation temperature to initiate living free radical polymerization to produce an A-B-A triblock copolymer.
2 more elements
Dependencies are inferred from the claim text.