Abstract: The strength and integrity of hydrophilic polyurethane resins prepared by reacting a diol component, an organic chain extender and an organic diisocyanate are improved by critical selection of the diol component, the amount of water in the reaction mixture and the mole ratios of the reactants. The diol component is at least one of (1) a long chain poly(oxyethylene) glycol of molecular weight above 2500 and (2) a medium chain poly(oxyethylene) glycol or polyester glycol of 250-2500 molecular weight. The chain extender is a difunctional compound having a molecular weight of less than 250. The amount of water in the reaction mixture is 0.5 to 2.5 weight % and the urea content of the resins is from about 13.6 to 33.7 weight %.

Abstract: The strength and integrity of hydrophilic polyurethane resins prepared by reacting a diol component, an organic chain extender and an organic diisocyanate are improved by critical selection of the diol component, the amount of water in the reaction mixture and the mole rations of the reactants. The diol component is at least one of (1) a long chain poly(oxyethylene) glycol of molecular weight above 2500 and (2) a medium chain poly(oxyethylene) glycol or polyester glycol of 250-2500 molecular weight. The chain extender is a difunctional compound having a molecular weight of less than 250. The amount of water in the reaction mixture is 0.5 to 2.5 weight % and the urea content of the resins is from about 13.6 to 33.7 weight %.

Abstract: Thermally reversible polyurethane hydrogels are formed by adding water to a gel forming hydrophilic polyurethane polymer produced by reacting under anhydrous conditions a non-aromatic organic diisocyanate with a glycol component in an NCO/OH mole weight ratio of from about 0.900/1 to about 0.980/1, the glycol component having a number average molecular weight of from about 1000 to 3500 wherein the percentage by weight of the diisocyanate in the reaction mixture is from about 7% to about 20%. The hydrogels are solids at room temperature but liquify at higher temperatures such as body temperature and therefore are useful as carriers for the protection, delivery and sustained release of a variety of active agents including pharmaceuticals, cosmetics, living cells and organisms.

Abstract: Polyurethane acrylate compositions are obtained by reacting 100 parts of a hydrophilic polyurethane resin in the presence of from about 10 to about 50 parts of an acrylate. The resulting products will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane acrylate compositions may be molded to form shaped products that swell in water and have a variety of uses.

Abstract: Hydrophilic polyurethane polymers having carboxy groups in the polymer backbone are prepared by reacting a polyol component, an ester of a carboxylic acid and a polyisocyanate to form a polyurethane intermediate. The intermediate is then saponified and the saponified product neutralized to form free carboxy groups. The water absorption of the intermediates and saponified polymers is above 10% and the polyurethanes may range from rigid solids to gel-like, high water absorptive polymers. Neutralization of the carboxy group with ammonium hydroxide produces a water soluble polyurethane which becomes water insoluble when the ammonia is driven off. The carboxy groups introduced into the polymeric chain provide reactive sites for attachment of various side-groups and also allow for various curing procedures.

Abstract: Shaped three-dimensional structures formed of polyurethane polyene compositions obtained by reacting from about 10 to about 50 parts by weight of a polyene in the presence of about 100 parts by weight of a hydrophilic polyurethane resin. The resulting products will swell and increase in weight upon immersion in water and are permeable to gases, moisture vapor, ions, and other low molecular weight species. The hydrophilic polyurethane polyene compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory.

Abstract: Three-dimensional substrates having on at least one surface a coating formed of a polyurethane polyene composition obtained by reacting from about 10 to about 50 parts by weight of a polyene in the presence of about 100 parts by weight of a hydrophilic polyurethane resin. Transparent substrates are rendered antifogging by such coatings. The drag resistance of boat hulls may be decreased by a coating of the compositions and marine growth thereon may be inhibited by incorporating substances such as mercurous acetate in the coating.

Abstract: Polyurethane polyene compositions are obtained by reacting from about 10 to about 50 parts by weight of a polyene in the presence of about 100 parts by weight of a hydrophilic polyurethane resin. The resulting products will swell and increase in weight upon immersion in water and are permeable to gases, moisture vapor ions, and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory.

Abstract: Polyurethane quaternary ammonium salts are obtained by heating a solution of a polyurethane resin characterized by having present in the polymer backbone hydroxyl groups and at least one substituent selected from the group consisting of carboxylate radicals and carboxyl radicals dissolved in a water-miscible organic solvent for the resin at a temperature above 64.degree. C. and below the decomposition temperature of said polyurethane resin with an organic chloride for a period of time; adding a strong base to the reaction mixture and continuing to heat said mixture to form a polyurethane quaternary ammonium hydroxide in solution; and precipitating the polyurethane quaternary ammonium hydroxide by pouring the reaction mixture into an excess of water.

Abstract: Polyurethane diacrylate compositions are obtained by reacting a diacrylate in the presence of from about 65 to about 95 weight percent of a hydrophilic polyurethane resin. The compositions will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory. The compositions are useful as carriers for pharmacologically active agents in forming an oral delivery system.

Abstract: Gas and ion permeable membranes useful as burn dressings, surgical drapes and the like formed of polyurethane diacrylate compositions obtained by reacting a diacrylate in the presence of from about 65 to about 95 weight percent of a hydrophilic polyurethane resin. The compositions will form a hydrogel upon immersion in water and are also permeable to other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory.

Abstract: Canulae formed of or having a coating of polyurethane diacrylate compositions obtained by reacting a diacrylate in the presence of from about 65 to about 95 weight percent of a hydrophilic polyurethane resin. The compositions will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory.

Abstract: Surgical implants, intrauterine devices and the like formed of polyurethane diacrylate compositions obtained by reacting a diacrylate in the presence of from about 65 to about 95 weight percent of a hydrophilic polyurethane resin. The compositions will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory. The shaped products contain distributed therein a desired medicament.

Abstract: Polyurethane diacrylate compositions are obtained by reacting a diacrylate in the presence of from about 30 to about 95 weight percent of a hydrophilic polyurethane resin. The resulting products will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory. The compositions are useful for making contact lenses and numerous forms of surgical devices, among other things.

Abstract: Polyurethane diacrylate compositions are obtained by reacting a diacrylate in the presence of from about 30 to about 95 weight percent of a hydrophilic polyurethane resin. The resulting products will form a hydrogel upon immersion in water and are permeable to gases, ions and other low molecular weight species. The hydrophilic polyurethane diacrylate compositions may be molded to form shaped products that are dimensionally stable after repeated exposure to boiling water and exhibit memory.