Water blown, hydrophilic, open cell polyurethane foams, method of making such foams and articles made therefrom

A process for preparing a water blown, open cell, hydrophilic polyurethane foam having a density between about 0.7 and about 2.0 lb/ft.sup.3, said process comprising:

• (i) reacting in one step a reaction mixture comprising:
• (a) an organic polyisocyanate;
• (b) water;
• (c) a reaction catalyst;
• (d) a poly(oxyalkylene) triol, chain terminated with propylene oxide a having a molecular weight in the range of about 2800 to about 6200;
• (e) a diol selected from the group consisting of diethylene glycol, ethylene glycol, polyethylene glycol, tetraethylene glycol, 1,4-butanediol, propylene glycol, and triethylene glycol, said diol having a molecular weight in the range of about 60 to about 250;
• and
• (f) a composition selected from the group consisting of (i) poly(oxyalkylene) diols chain terminated with ethylene oxide and having a molecular weight in the range of about 500 to about 4000, and (ii) polyfunctional polyols, chain terminated with propylene oxide and having a molecular weight in the range of about 250 to about 1000;
• wherein the ratio of NCO to OH groups for the polyisocyanate, diol and polyols is in the range of about 0.5:1 to about 0.9:1, and wherein about 10 to about 40 wt. % of the total weight of the diols and polyols of components (d), (e), and (f) is (d), about 5 to about 60 wt. % is (e), and about 4 to about 60 wt. % is (f);
• and
• (ii) producing a water blown, open cell, hydrophilic polyurethane foam of said density.

An article of manufacture comprising a water blown, open cell, hydrophilic polyurethane foam having a density between about 0.7 and about 2.0 lb/ft.sup.3, said polyurethane being the reaction product of:

• (a) an organic polyisocyanate;
• (b) water;
• (c) a reaction catalyst;
• (d) a poly(oxyalkylene) triol, chain terminated with propylene oxide and having a molecular weight in the range of about 2800 to about 6200;
• (e) a diol selected from the group consisting of diethylene glycol, ethylene glycol, polyethylene glycol, tetraethylene glycol, 1,4-butanediol, propylene glycol, dipropylene glycol, and triethylene glycol, said diol having a molecular weight in the range of about 60 to about 250;
• and
• (f) a poly(oxyalkylene) diol chain terminated with ethylene oxide and having a molecular weight in the range of about 500 to about 4000;
• wherein the ratio of NCO to OH groups for the polyisocyanate, diols and polyols is in the range of about 0.5:1 to about 0.9:1, and further wherein about 10 to about 50 weight percent of the total weight of the diols and polyols of components (d), (e), and (f) is component (d), about 5 to about 60 wt. % is (e), and about 4 to about 60 wt. % is (f).