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US 6,143,820 AGranted
Preparation of a low polydisperse water-soluble polymeric composition
AssigneeThe Dow Chemical Company
InventorsJohn Klier, Thomas H. Kalantar, Christopher J. Tucker, Erin D. O'Driscoll, Andrew T. Graham
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Abstract
A water-soluble polymer having a low polydispersity index and controlled molecular weight can be prepared by oxidative degradation and shearing of a water-swellable crosslinked polymer or by hydrolysis of the crosslinked polymer to a high molecular weight soluble polymer, followed by oxidative degradation of the high molecular weight polymer.
Claims7
A method of preparing a low polydisperse, water-soluble polymer comprising the steps of:
- a) hydrolyzing a water-swellable crosslinked polymer that contains covalently bonded hydrolyzable crosslinking groups to form a first water-soluble polymer;
- and
- b) oxidatively degrading the first water-soluble polymer to form a second water-soluble polymer that has a lower number average and weight average molecular weight and a lower polydispersity than the first water-soluble polymer.
Dependencies are inferred from the claim text.