Synthesis of diblock copolymers comprising poly(2‐vinylpyridine‐co‐acrylonitrile) and polystyrene blocks by nitroxide‐mediated radical polymerization

AbstractNitroxide‐mediated radical copolymerization of 2‐vinylpyridine (2VP) with acrylonitrile (AN) at various mole fractions of 2VP in the feed at 125°C was studied. An alkoxyamine containing the diethoxyphosphoryl group (MAMA‐SG1) or a two‐component system of 2,2′‐azobis(isobutyronitrile) or dibenzoyl peroxide in combination with nitroxyl radicals TEMPO were used for the initiation; in addition, spontaneous thermal radical copolymerization of both the comonomers was performed in the presence of a nitroxide. The obtained nitroxide‐terminated 2VP‐AN copolymers showed a low polydispersity (Mw/Mn ∼ 1.2). They initiated polymerization of styrene (S) giving poly(2VP‐co‐AN)‐block‐polyS diblock copolymers; however, in dependence on the used macroinitiator, the resulting products might be markedly contaminated with inactive polymer chains. On the other hand, the 2VP‐AN copolymerization, which was initiated at 125°C with a TEMPO‐terminated polyS, proved to be an efficient synthetic route for the preparation of diblock copolymers comprising blocks of polyS and poly(2VP‐co‐AN). The synthesized copolymers were characterized by NMR spectroscopy and size‐exclusion chromatography. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007