High molecular weight terpolymers of acrylamide, acrylic acid salts and alkylacrylamide

Claim 1

A homogeneous micellar redox copolymerization process for the formation of a copolymer of acrylamide and an oil soluble higher alkylacrylamide wherein said copolymer has an intrinsic viscosity of at least about 12 dl/g in 2 weight percent NaCl, which comprises the steps of: (a) forming a homogeneous mixture of a surfactant, acrylamide, water and an oil soluble higher alkylacrylamide wherein the concentration of acrylamide is about 10 to about 40 weight percent, the concentration of oil soluble higher alkylacrylamide is about 0.01 to about 4 weight percent, and the concentration of the surfactant is about 1 to 15 weight percent; and (b) deoxygenating said homogeneous reaction mixture by replacing the oxygen with an inert gas; (c) adding a sufficient quantity of a redox catalyst initiator to the said deoxygenated homogeneous reaction mixture to cause copolymerization of said deoxygenated homogeneous mixture at a temperature maintained below about 40° C. without the formation of substantial amounts of particulates or a separate phase; and (d) hydrolyzing said copolymer by the addition of alkali metal base to give a terpolymer which is characterized by the formula: ##STR2## wherein R 1 is a C 6 to C 22 straight chain or branched alkyl or cycloalkyl group; R 2 is the same or different alkyl group as R 1 , or hydrogen; M + is an alkali metal or ammonium cation, wherein x is about 0.50 to about 0.999; y is about 0.001 to about 0.05; and z is about 0.05 to about 0.50.