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US 10,851,214 B2Granted
Polymer gels, method of preparation and uses thereof
AssigneeRhodia Acetow GmbH
InventorsGuainumbi Medeiros, Renata Brito
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Abstract
The invention relates to a method for the preparation of a polymer gel, comprising cross-linking a polymer by using a cyclic dianhydride of carboxylic acid as cross-linking agent and treating the polymer gel with bicarbonate. The invention further concerns the polymer gel obtainable by the method of the invention and the uses thereof in various applications.
Claims8
A method for preparing a polymer gel, the method comprising the steps of:
- (a0) adding a cyclic monoanhydride to a solution comprising a polymer comprising hydroxyl groups, in the presence of a catalyst,
- wherein the polymer comprising hydroxyl groups is cellulose acetate with a degree of substitution of OH groups between 1.3 and 3;
- and
- wherein the cyclic monoanhydride is phthalic anhydride or 1,2,4-benzenetricarboxylic anhydride;
- (a) adding a cyclic dianhydride to the solution comprising the polymer comprising hydroxyl groups in the presence of the catalyst, thereby forming a solution including hydrophilic polymer,
- wherein the molar ratio of dianhydride per hydroxyl group of the polymer in the solution of step (a) is about from 0.1 to 2.0 mol/mol;
- and
- wherein the molar ratio of monoanhydride per hydroxyl group of the polymer in the solution of step (a0) is about from 0.1 to 1 mol/mol;
- (b) maintaining the solution including hydrophilic polymer of step (a) under conditions suitable for cross-linking of the hydrophilic polymer by the cyclic dianhydride, thereby forming a polymer gel;
- and
- (c) treating the polymer gel with an aqueous solution of bicarbonate.
8 more elements
A method for preparing a polymer gel, the method comprising the steps of:
- (a0) adding a cyclic monoanhydride to a solution comprising a polymer comprising hydroxyl groups, in the presence of a catalyst,
- wherein the polymer comprising hydroxyl groups is cellulose diacetate, cellulose triacetate, or a mixture thereof, or cellulose dipropionate, cellulose tripropionate or a mixture thereof, or respective mixtures thereof;
- and
- wherein the cyclic monoanhydride is phthalic anhydride;
- (a) adding a cyclic dianhydride to the solution comprising the polymer comprising hydroxyl groups in the presence of the catalyst, thereby forming a solution including hydrophilic polymer;
- wherein the molar ratio of dianhydride per hydroxyl group of the polymer in the solution of step (a) is about from 0.5 to 1.5 mol/mol;
- and
- wherein the molar ratio of monoanhydride per hydroxyl group of the polymer in the solution of step (a0) is about from 0.1 to 1 mol/mol;
- (b) maintaining the solution including hydrophilic polymer of step (a) under conditions suitable for cross-linking of the hydrophilic polymer by the cyclic dianhydride, thereby forming a polymer gel;
- and
- (c) treating the polymer gel with an aqueous solution of bicarbonate.
8 more elements
Dependencies are inferred from the claim text.