PVA hydrogel
First Claim
1. A method of making a covalently cross-linked vinyl polymer hydrogel comprising the steps of:
- providing a physically associated vinyl polymer hydrogel having a crystalline phase;
exposing the physically associated vinyl polymer hydrogel to an amount of ionizing radiation providing a radiation dose in the range of about 1-1,000 kGy effective to form covalent crosslinks; and
removing physical associations by exposing the irradiated vinyl polymer hydrogel to a temperature above the melting point of the physically associated crystalline phase to produce a covalently cross-linked vinyl polymer hydrogel.
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Accused Products
Abstract
The present invention provides methods of making covalently crosslinked vinyl polymer hydrogels having advantageous physical properties, and covalently crosslinked vinyl polymer hydrogel compositions made by such methods, as well as articles of manufacture comprising such covalently crosslinked vinyl polymer hydrogel compositions. The physical properties of the produced hydrogels can be adjusted by varying controlled parameters such as the proportion of physical associations, the concentration of polymer and the amount of radiation applied. Such covalently crosslinked vinyl polymer hydrogels can be made translucent, preferably transparent, or opaque depending on the processing conditions. The stability of the physical properties of the produced vinyl polymer hydrogel can be enhanced by controlling the amount of covalent crosslinks.
214 Citations
38 Claims
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1. A method of making a covalently cross-linked vinyl polymer hydrogel comprising the steps of:
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providing a physically associated vinyl polymer hydrogel having a crystalline phase; exposing the physically associated vinyl polymer hydrogel to an amount of ionizing radiation providing a radiation dose in the range of about 1-1,000 kGy effective to form covalent crosslinks; and removing physical associations by exposing the irradiated vinyl polymer hydrogel to a temperature above the melting point of the physically associated crystalline phase to produce a covalently cross-linked vinyl polymer hydrogel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of making a covalently cross-linked vinyl polymer hydrogel comprising the steps of:
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providing a vinyl polymer solution comprising a vinyl polymer dissolved in a solvent; heating the vinyl polymer solution to a temperature elevated above the melting point of the physical associations of the vinyl polymer; inducing gelation of the vinyl polymer solution; controlling the gelation rate to form crystalline physical associations in the vinyl polymer hydrogel; exposing the physically associated vinyl polymer hydrogel to a dose of ionizing radiation of about 1-1,000 kGy effective to produce covalent crosslinks; and melting the vinyl polymer hydrogel in a solvent to remove physical associations, thereby making a covalently cross-linked vinyl polymer hydrogel. - View Dependent Claims (34, 35, 36, 37, 38)
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Specification