| 摘要 |
A hydrophilic polyurethane product comprises: a cellular polyurethane plastic produced by a process which comprises reacting in the presence of a blowing agent an organic polyisocyanate with an organic compound having a plurality of hydroxyl groups reactive with an -NCO group; and polyacrolein added to the cellular plastic after the formation thereof, as a polyacrolein-sulphurous acid reaction product, the hydrophilic polyurethane product retaining the cellular structure of the initial polyurethane sponge. The polyurethane may be prepared from the polyisocyanate and a polyamine, polyalcohol, aminoalcohol, polyhydroxyester, polythiol, polysulphonamide, polyglycol or alkyd resin containing hydroxyl and carboxyl groups. In Examples, foams are prepared from (1) a prepolymer (from HO(C2H4O)a(C3H6O)b -(C2H4O)cH in which the polyoxypropylene has M.W. 1500 to 1800 and a 10% oxyethylene content, polypropylene glycol of M.W. 400 and toluene diisocyanate), by adding polydimethylsiloxane, Benzidine Yellow, titanium dioxide coated calcium sulphate particles, and a mixture of water, triethylamine and diethylethanolamine. The product is crushed to break cell walls and then cured at 185-190 DEG F.; (2) a polyester of adipic acid and diethylene glycol, toluene diisocyanate, methyl diethanolamine and water. The sponges are immersed in a heated solution formed by agitating polyacrolein (M.W. 30,000) with water and passing sulphur dioxide through the mixture. Excess solution is wrung out and the sponges are washed with water or sodium carbonate solution until free of acid reaction.
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