Atom transfer radical polymerization of methyl acrylate, methyl methacrylate and styrene in the presence of trolamine as a highly effective promoter

Transition metal-mediated atom transfer radical polymerization (ATRP) is a “living”/controlled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work, trolamine was found to significantly enhance the catalytical performance of CuBr/N,N,N′,N′-tetrakis(2-pyridylmethyl) ethylenediamine (CuBr/TPEN) and CuBr/tris[2-(dimethylamino) ethylamine] (CuBr/Me6TREN). With the addition of 25-fold molar amount of trolamine relative to CuBr, the catalyst loadings of CuBr/TPEN and CuBr/Me6TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05, respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly(methyl acrylate), poly(methyl methacrylate) and polystyrene with molecular weights close to theoretical values and low polydispersities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application.

Graphical abstractTrolamine was found to remarkably improve the catalytical performance of CuBr/TPEN and CuBr/Me6TREN and significantly increase the polymerization rate in ATRP of methyl acrylate, methyl methacrylate and styrene catalyzed by the two catalysts. Correspondingly, the catalyst loadings of CuBr/TPEN and CuBr/Me6TREN could be reduced by as much as 100 times and 20 times respectively in the presence of trolamine as a promoter.Figure optionsDownload full-size imageDownload as PowerPoint slide