Chain Transfer Kinetics of Rhodixan^® A1 RAFT/MADIX Agent

Rhodixan^® A1 is the trade name for O-ethyl S-(1-methoxycarbonylethyl)dithiocarbonate, a RAFT/MADIX agent used by Syensqo to produce block copolymer additives for aqueous formulations on an industrial scale. Chain transfer coefficients to Rhodixan^® A1 determined for 25 different styrenic, acrylate, and acrylamide monomers were relatively low (0.6 < C_tr < 3.8) and evolved in the following order: styrenics < acrylates < acrylamides. The corresponding interchain transfer coefficients followed the same trend (0.6 < C_tr,PnXA1 < 5.9). In all cases, polymers with predetermined M are obtained at high monomer conversion, with dispersities inversely proportional to C_tr,PnXA1 in most cases. With the added benefit of the established excellent reactivity of Rhodixan^® A1 towards unconjugated monomers such as vinyl esters, diallyl, or N-vinyl monomers, RAFT/MADIX is a fantastic technological toolbox for tailor-making complex copolymers from monomers of highly disparate reactivities.