Hydrophilic polyurethane foam

A process for preparing flexible, hydrophilic polyurethane foam from a reaction mixture comprised of an organic polyisocyanate, a foaming agent, a reaction catalyst, and three polyether polyols, namely,

• a. a first polyol having a molecular weight of about 3,000- 5,000 which is the product of sequentially oxyalkylating an aliphatic triol first with ethylene oxide and then with propylene oxide using a molar ratio, ethylene oxide:
• propylene oxide, from about 0.3:1 to about 1.6:1, said first polyol being used in a weight proportion from about 10 to about 50 percent of the combined weights of said three polyols,
• b. a second polyol having a molecular weight of about 2,000-5,000 which is the product of sequentially oxyalkylating an aliphatic diol first with ethylene oxide and then with propylene oxide using a molar ratio, ethylene oxide:propylene oxide, from about 0.3:1 to about 1.4:1, said second polyol being used in a weight proportion of about 20-50 percent of the combined weights of said three polyols, and
• c. a third polyol having a molecular weight of about 2,400-5,000 which is the product of oxyalkylating an aliphatic triol with a random mixture of ethylene oxide and propylene oxide, the content of ethylene oxide in the mixture being about 5-25% by weight, said third polyol being used in a proportion of about 10-50 percent of the combined weights of said three polyols.