Patent ID: 8907008

Claim:
A process comprising the steps of: a) contacting a polyisocyanate branching agent with a stoichiometric excess of a water-soluble polyalkylene glycol under such conditions to form a mixture of the polyalkylene glycol and a branched poly-hydroxyalkylene oxide urethane; b) contacting the mixture of the polyalkylene glycol and the branched poly-hydroxyalkylene oxide urethane with a stoichiometric excess of a difunctional linking agent selected from the group consisting of diisocyanates, epihalohydrins, and gem-dihalides, under such conditions to form a branched urethane polymer containing hydroxyl-reactive end groups; and c) contacting the branched urethane polymer containing hydroxyl-reactive end groups with a capping agent under such conditions to form a hydrophobically modified alkylene oxide urethane, wherein the capping agent is characterized by either of the following formulas: R 2 (OY) x —ZH or where R 2 is a C 4 -C 30 -alkyl, -aryl, or -aralkyl group; R 3 is H or a C 4 -C 30 -alkyl, -aryl, or -aralkyl group; R 4 is a C 4 -C 30 -alkyl, -aryl, or -aralkyl group; Y is a C 2 -C 8 -alkylene group; W is N or P; x is an integer from 0 to 200; and Z is O or NH.