The present invention provides telomeric copolymers of acrylic and methacrylic acid which further comprise an olefin polymerization residue and have one or more phosphorus acid groups wherein the phosphorus acid group comprises one or more phosphorus atom in the +1 oxidation state or in the +3 oxidation state, or both. In addition the present invention provides methods of making the telomeric copolymers comprising aqueous solution copolymerizing a monomer mixture comprising acrylic acid and methacrylic acid in the presence of a phosphorus acid group containing reactant having a phosphorus atom in the +1 oxidation state, and thermally treating the resulting telomeric copolymer at 175° C. or higher for a sufficient time to decarboxylate the copolymer.