We apply the RAFT/MADIX technique to the micellar copolymerization of acrylamide and 2-acrylamido-2methylpropanesulfonic acid sodium salt with a hydrophobic monomer, 4-tert-butylstyrene. The resulting polymers have wellcontrolled molecular weight distributions. In the presence of sodium dodecyl sulfate, the polymerization is better controlled by an oligo-acrylamide chain transfer agent (PAm 7 -XA1) than by Rhodixan A1. The associative character of the polymer is maintained under RAFT polymerization conditions and chains can be extended to form block copolymers with associative segments.