Atom transfer radical polymerization (ATRP) with concurrent reverse and normal initiation process was investigated. Bulk polymerizations of both n-butyl acrylate (BA) and styrene (St) were conducted using CuBr2 complexed with 1 equiv of tris(2-(dimethylamino)ethyl)amine (Me6-TREN) as the catalytic system, initiated by 2,2′-azobis(isobutyronitrile) (AIBN) and an alkyl halide (RX). Polymerization of BA at 60 or 90°C provided well-defined polymers with molecular weights up to 40 000 g/mol and low polydispersities (Mw/Mn < 1.10). Similar results were obtained for the polymerization of styrene at 110°C. The effects of polymerization temperature and solubility were studied in order to moderate the high activity of the catalyst and the poor solubility of the Cu(II) complex in monomers. Additionally, other parameters influencing this ATRP process are discussed.

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Summary: Ligands suitable for atom transfer radical polymerization (ATRP) were prepared by the Michael addition of several acrylates (allyl, benzyl, butyl, 2‐ethylhexyl, and 3‐(dimethoxymethylsilyl)propyl acrylates) with tris(2‐aminoethyl)amine (TREN). These ligands, readily prepared from inexpensive precursors, were used for the preparation of catalyst complexes suitable for polymerization of (meth)acrylates and styrene, providing activity comparable to catalysts currently used for these monomers. Catalysts containing ligands with a dimethoxymethylsilyl substituent were examined for copper removal after the reaction mixture was contacted with silica gel.magnified image

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