Control of polymer structure by a chain-transfer reaction in the radical polymerization of acrylamide by β-mercaptopropionic acid and 1,2,6-hexanetriol trithioglycolate

Star polymer synthesis by radical polymerization of acrylamide (AM) in the presence of thiol compounds was investigated. When 1,2,6-hexanetriol trithioglycolate (HTTG), as a trithiol compound, was used the molecular weights of the polymers were about 3 times those obtained in the presence of beta -mercaptopropionic acid, as a monothiol compound, at the same concentration of thiol compounds in the feed. From viscosity measurements of the polymers and analysis of the H-1 NMR spectra of the polymers, we presumed that a starshaped polymer of AM could be synthesized by radical polymerization in the presence of HTTG.