Synthesis of aromatic oxazolyl- and carboxyl-functionalized polymers: Atom transfer radical polymerization of styrene initiated by 2-[(4-bromomethyl) phenyl]-4,5-dihydro-4,4-dimethyloxazole

The synthesis of a new compound, 2-[(4-bromomethyl)phenyl]-4,5-dihydro-4,4- dimethyloxazole (1), and its utility in the synthesis of oxazoline- functionalized polystyrene by atom transfer radical polymerization (ATRP) methods are described. Aromatic oxazolyl-functionalized polymers were prepared by the ATRP of styrene, initiated by (1) in the presence of copper(I) bromide/2,2′-bipyridyl catalyst system, to afford the corresponding α-oxazolyl-functionalized polystyrene (2). The polymerization proceeded via a controlled free radical polymerization process to produce the corresponding α-oxazolyl-functionalized polymers with predictable number-average molecular weights, narrow molecular weight distributions in high-initiator efficiency reactions. Post-ATRP chain end modification of α-oxazolyl-functionalized polystyrene (2) to form the corresponding α-carboxyl-functionalized polystyrene (3) was achieved by successive acid-catalyzed hydrolysis and saponification reactions. The polymerization processes were monitored by gas chromatography analyses. The unimolecular-functionalized initiator and functionalized polymers were characterized by thin layer chromatography, spectroscopy, size exclusion chromatography, and nonaqueous titration analysis. © 2011 Wiley Periodicals, Inc.