Biodegradable hydrophilic foams and method

An isocyanate-capped polyether polyol having an isocyanate functionality of at least 2, said polyol comprising a mixture, prior to capping, of (a) an aliphatic alcohol having from 3 to 8 hydroxyl groups per mole and a molecular weight of less than about 1,000 and (b) an essentially linear hydroxy terminated polyether having a molecular weight not exceeding about 4,000, wherein the hydroxyl groups of the polyether are esterified by reaction with a monobasic hydroxy carboxylic acid containing up to 20 carbon atoms.

An isocyanate-capped polyether polyol having an isocyanate functionality of at least 2, said polyol corresponding to the formula:

• T--L--A).sub.x wherein T is the residue of an aliphatic alcohol, x is an integer from 3 to 8 corresponding to the number of hydroxyl groups in the alcohol prior to reaction to form said residue, L is a hydroxy carboxylic acid residue, said alcohol residue bonded to said acid residue by means of an ester linkage, and A is an essentially linear hydroxy terminated polyether residue bonded to said acid residue by an ether linkage, the terminal free hydroxyl group of said polyether being linked by a urethane linkage to the isocyanate used in capping the polyol.