Microporous polyurethane hydrogels, method and composites with natural and other synthetic fibers or films
AssigneeUnion Carbide Corporation
InventorsAllen Paul Jones, Jr., Robert John Knopf, Claude Milton Conner
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Abstract
Microporous polyurethane hydrogels of high water swellability comprising lightly crosslinked polymers of isocyanate terminated prepolymers which are the reaction product of (i) poly(alkyleneoxy) polyol with (ii) organic diisocyanate that has been lightly crosslinked with (iii) water or an organic polyamine are produced by impregnating the isocyanato terminated prepolymer solution prior to contact with the crosslinking agent with a minor significant amount of a liquid non-solvent.
Claims33
An article of manufacture comprising a composite of (I) a shaped microporous, water swellable, lightly crosslinked, hydrogel polymer article of the isocyanato terminated prepolymer comprising the reaction product of:
- i. a poly(alkyleneoxy) polyol having an average molecular weight up to about 25,000 wherein the alkyleneoxy group contains from 2 to 4 carbon atoms, and
- ii. an organic diisocyanate, said prepolymer impregnated with a minor significant amount of a liquid non-solvent prior to lightly crosslinking thereof with an equivalent amount of a crosslinking agent of the group:
- iii. water or organic polyamine;
- wherein said poly(alkyleneoxy) polyol is a mixture of a major amount of a poly(ethyleneoxy) diol having an average molecular weight of from about 4,000 to about 25,000 and a minor amount of a higher polyol of the group poly(alkyleneoxy) triol or poly(alkyleneoxy) tetrol having from 2 to 4 carbon atoms in the alkyleneoxy group or aliphatic polyhydroxyl compound of the formula C.sub.n H.sub.2n.sub.+2.sub.-m (OH).sub.m wherein n has a value of 3 to 6 and m has a value of 3 to 4, or mixtures thereof, said triol or tetrol having an average molecular weight of from about 92 to 5,000, wherein the mole ratio of diol to higher polyol in said mixture is from about 6:1 to 40:1;
- wherein the equivalents ratio of isocyanato groups to hydroxyl groups is from about 1.2:1 to about 1.6:1;
- wherein the organic polyamine is a primary or secondary diamine or triamine and wherein the equivalents of reactive crosslinking groups in said crosslinking agent used is equivalent to the number of equivalents of isocyanato groups present in said prepolymer;
- in combination with (II) a natural or a different synthetic fiber or film.
A method for producing a shaped microporous, lightly crosslinked, water swellable, hydrogel polymer article which comprises the steps of:
- A. producing an organic solvent solution of an isocyanato terminated prepolymer comprising the reaction product of:
- i. poly(alkyleneoxy) polyol having an average molecular weight up to about 25,000, wherein the alkyleneoxy group contains from 2 to 4 carbon atoms, and
- ii. organic diisocyanate, wherein said poly(alkyleneoxy) polyol is a mixture of a major amount of a poly(ethyleneoxy) diol having an average molecular weight of from about 4,000 to about 25,000 and a minor amount of a higher polyol of the group poly(alkyleneoxy) triol or poly(alkyleneoxy) tetrol having from 2 to 4 carbon atoms in the alkyleneoxy group or aliphatic polyhydroxyl compound of the formula C.sub.n H.sub.2n.sub.+2.sub.-m (OH).sub.m wherein n has a value of 3 to 6 and m has a value of 3 to 4 or mixture thereof, said triol or tetrol having an average molecular weight of from about 92 to 5,000, wherein the mole ratio of diol to higher polyol in said mixture is from about 6:1 to 40:1;
- and wherein the equivalents ratio of isocyanato groups to hydroxyl groups is from about 1.2:1 to about 1.6:1;
- B. impregnating said isocyanato terminated prepolymer solution with a minor significant amount of a liquid nonsolvent;
- C. extruding or spinning said impregnated isocyanato terminated solution into a crosslinking bath comprising:
- i. a crosslinking agent for the isocyanato terminated prepolymer of the group (a) water or (b) organic polyamine,
- wherein said polyamine is a primary or secondary diamine or triamine and wherein the equivalents of reactive crosslinking groups in said crosslinking agent used is equivalent to the number of equivalents of isocyanato groups present in said prepolymer;
- and
- D. recovering the lightly crosslinked, water swellable, shaped microporous hydrogel article.
Dependencies are inferred from the claim text.