The RAFT copolymerization of acrylic acid and acrylamide

The reversible addition-fragmentation chain transfer (RAFT) copolymerization of non-ionized acrylic acid with acrylamide in dimethyl sulfoxide is investigated and compared with the conventional free radical process carried out at the same conditions. The effect of the living nature of the RAFT process on overall polymerization rate and on copolymer composition is studied by in situ 1H NMR. The same values of reactivity ratios (rAA = 1.55 ± 0.02 and rAm = 0.75 ± 0.02) are estimated for both the processes, living and non-living. The copolymers prepared by RAFT polymerization exhibit well-controlled composition, with narrow distribution. This approach can be applied to the synthesis of copolymer standards at specific composition for direct calibration of size-exclusion chromatography.