Process for synthesizing thiol terminated polymers
AssigneeCommonwealth Scientific and Industrial Research Organisation
InventorsGraeme Moad, Ezio Rizzardo, San Hoa Thang
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Abstract
The present invention is directed to a process for the cleavage of one or more starting polymers having thiocarbonylthio groups of the formula —S—(C═S)— into derived polymers having thiol end groups of the formula —SH. The process includes contacting the aforedescribed starting polymers, with a reagent having the formula Xa Yb, wherein Xa is a nucleophilic group and Yb is an extracting group that results in the starting polymer and a byproduct, which is then separated from the derived polymer by conventional separation processes. The derived polymer is free from any odor or color that is sometimes associated with the starting polymer and it can be used in making optical lenses, such as contact lenses.
Claims19
A process for removing one or more groups of the formula —S—(C═S)— from a starting polymer, which is in the form of a solution, dispersion, or a combination thereof, said process comprising:
- contacting said starting polymer with one or more reagents to form at least (i) a derived polymer absent one or more groups of the formula —S—(C═S)—, and (ii) a byproduct, said one or more reagents selected from the group consisting of 2-(dimethylamino)ethylamine, 3-dimethylamino-1-propylamine, 4-amino-2,2,6,6-tetramethylpiperidine, and a reagent of the formula:
- wherein
- in said formula is a polymer moiety;
- and
- separating said byproduct from said derived polymer.
Dependencies are inferred from the claim text.