Free radical copper(II)-enolate polymerization initiators
AssigneeThe University of Akron
InventorsH. James Harwood, Stephen D. Goodrich
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Abstract
The invention describes a redox initiating system consisting of Cu.sup.II salts, enolizable aldehydes and ketones, and various combinations of coordinating agents for Cu.sup.II, coordinating agents for Cu.sup.I, and a strong amine base that is not oxidized by Cu.sup.II. In particular, Cu.sup.II octanoate/dibenzyl ketone/pyridine/triethylamine/triphenylphosphine systems are effective. In addition to initiating free radical polymerizations and copolymerizations, this initiating system can be applied to the synthesis of functionalized telechelics, polymers with ketone linkages in the backbone, block and graft copolymers consisting of free-radical and step-growth polymer blocks, and crosslinking reactions.
Claims11
A process for the synthesis of a polymer with controlled, predictable polymer end-group structures under mild oxidative conditions thereby permitting other useful functional groups to be present on the polymer end-groups comprising the steps of:
- (a) adding aldehydes or ketones bearing enolizable hydrogen atoms into a reaction vessel;
- (b) inducing an enolate oxidation reaction with a Cu.sup.II salt to form an enolate radical which has a greater electron donating capability toward the Cu.sup.II ion than the non-enolized or enol form of the aldehydes or ketones, the Cu.sup.II converting the initiator into .alpha.-carbonyl free radicals capable of initiating free radical polymerizations;
- and
- (c) reacting the enolate radical with a free-radical polymerizable monomer at a temperature from about -100.degree. C. to about +200.degree. C., for a reaction time from about 1 second to about 48 hours.
Dependencies are inferred from the claim text.