Patent ID: 7989554

Claim:
A method of preparing a polyalkylene oxide carboxylic acid, consisting essentially of: (a) reacting a polyalkylene oxide with a base, in a first solvent system, for a time period ranging from about 10 minutes to about 60 minutes; (b) reacting the product of step (a) in a second solvent system, with a tertiary alkyl haloacetate for a time period up to about 1 hour to form a tertiary alkyl ester of a polyalkylene oxide; and (c) reacting the tertiary alkyl ester of a polyalkylene oxide obtained from step (b) with an acid to form a polyalkylene oxide carboxylic acid, wherein the reaction of steps (a) and (b) are conducted at a temperature that ranges from about 10° C. to about 35° C.