Nitroxide-mediated homopolymerization and copolymerization of 2-vinylpyridine with styrene

Homopolymerization and copolymerization of 2‐vinylpyridine (2VP) with styrene (S) at 125°C in the presence of 2,2,6,6‐tetramethyl piperidin‐1‐yloxyl (TEMPO) radicals have been studied. The homopolymerization was carried out with 2,2′‐azobis(isobutyronitrile) (AIBN) as a thermal initiator or without AIBN in the initial reaction mixture. In the copolymerization initiated with AIBN, the molar fraction of 2VP in the feed, F2VP, varied in the range of 0.1–0.9; F2VP = 0.65 was found to be the azeotropic composition. The linear semilogarithmic time–conversion plots demonstrated a pseudoliving nature of the polymerizations under study. The molecular weight–conversion dependences indicated the participation of side reactions, diminishing the number of TEMPO‐terminated polymer chains. The synthesized homopolymers and copolymers were characterized using size‐exclusion chromatography (SEC), nitrogen analysis, and NMR spectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2024–2030, 2001