Atom transfer radical polymerization of hexyl acrylate and preparation of its “all‐acrylate” block copolymers

This investigation reports the polymerization of hexyl acrylate (HA) using atom transfer radical polymerization technique and subsequently the preparation of its di‐ and triblock copolymers with methyl methacrylate. Atom transfer radical polymerization of HA was investigated using different initiators and CuBr or CuCl as catalyst in combination with varying ligands, e.g., 2,2′‐bipyridine and N,N,N′,N″,N″‐pentamethyl diethylenetriamine. Reaction parameters were adjusted to successfully polymerize HA with well‐defined molecular weights and narrow polydispersity indices. The polymerization was better controlled by the addition of polar solvents, which created a homogeneous catalytic system. UV–vis analysis showed that the polar solvent, acetone coordinated with copper (I), changes the nature of the copper catalyst, thereby influencing the dynamic equilibrium of activation–deactivation cycle. This resulted in improved control over polymerization as well as in lowering the polydispersity indices, but at the cost of polymerization rate compared with the bulk process. The presence of ? Br end group in the polymer chains was confirmed by ¹H NMR as well as MALDI‐TOF mass analysis. In addition, poly(hexyl acrylate) was used as macroinitiator to prepare various “all‐acrylate” block (diblock, triblock) copolymers that were characterized by GPC and ¹H NMR. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3499–3511, 2008