Thiophenol derivatives as a reducing agent for in situ generation of Cu(I) species via electron transfer reaction in copper-catalyzed living/controlled radical polymerization of styrene

The copper-catalyzed living radical polymerization (LRP) of styrene (St) was carried out in the presence of thiophenol derivative such as sodium thiophenolate (PhSNa) or p-methoxythiophenol as a reducing agent for Cu(II) by using either 1-chloro-1-phenyl ethane or ethyl-2-bromoisobutyrate as an initiator and N,N,N′,N″,N″-pentamethyldiethylenetriamine as ligand at 110°C. Kinetic experiments were carried out to reveal the effect of PhSNa concentration on copper-catalyzed LRP of St. This technique was successfully applied for the preparation of both chain-extended polymer and block copolymer polystyrene-b-poly(methyl methacrylate). The obtained polymers were characterized using GPC, ¹H-NMR, and MALDI-TOF measurements.