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

Abstract

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. J Polym Sci Part A: Polym Chem, 2011.

The preparation of α‐bis and α,ω‐tetrakis aromatic oxazolyl‐ and carboxyl‐functionalized polymers using 1,1‐bis[4‐(2‐(4,4‐dimethyl‐1,3‐oxazolyl))phenyl]ethylene in atom transfer radical polymerization reactions

“…The synthesis of 3 by ATRP methods and the polymerization kinetic studies were effected using the general experimental procedures outlined by Matyjaszewski and co‐workers and Summers and co‐workers . In a typical procedure, under an argon atmosphere, a Schlenk flask was charged with copper (I) bromide (0.0599 g, 0.4177 mmol), bpy (0.1958 g, 1.254 mmol), 1 (0.1564 g, 0.4177 mmol), (1‐bromoethyl)benzene (0.0773 g, 0.4177 mmol) and freshly distilled xylene (1 mL).…”

“…In a separate experiment, the synthesis of 4 was effected by the in situ post‐ATRP chain‐end‐functionalization reaction of 3 with 1 , without the isolation and purification of the functionalized polymeric precursor according to the experimental procedures outlined by Summers and co‐workers . Under an argon atmosphere, precursor 3 was prepared by a typical ATRP procedure using a Schlenk flask charged with the following: copper (I) bromide (0.0477 g, 0.3325 mmol), bpy (0.1558 g, 0.9976 mmol), 1 (0.1245 g, 0.3325 mmol), (1‐bromoethyl)benzene (0.0615 g, 0.3323 mmol) and xylene (1 mL).…”

Syntheses of α‐bis(4‐aminophenyl)‐ and α,ω‐tetrakis(4‐aminophenyl)‐ functionalized polymers using 1,1‐bis(4‐aminophenyl)ethylene in atom transfer radical polymerization reactions

“…The chain‐end functionalization reaction of 3 with 1 as the functionalizing agent afforded the corresponding 4 according to the general ATRP chain‐end functionalization reaction developed in our laboratories . In a separate experiment, the precursor 3 was prepared by a typical ATRP reaction using the following reactants, stoichiometry and mode of addition of reactants: copper(I) bromide (0.0525 g, 0.3660 mmol), bpy (0.1715 g, 1.098 mmol), 1 (0.80 g, 0.3660 mmol), (1‐bromoethyl)benzene (0.068 g, 0.049 mL, 0.3660 mmol) and diphenyl ether (1.7 mL).…”

“…To our knowledge, the preparation of telechelic polymers with primary amine functional groups at both chain ends by direct ATRP methods has not been reported in the literature . Recently, the first, direct, in situ post‐ATRP chain‐end functionalization reaction was developed in our laboratories . For example, quantitative yields of α , ω ‐bis(oxazolyl)‐functionalized polystyrene were obtained by the in situ post‐ATRP chain‐end functionalization reaction of α ‐oxazolyl‐functionalized polystyrene with 4,5‐dihydro‐4,4‐dimethyl‐2‐[4‐(1‐phenylethenyl)phenyl]oxazole, without the need for isolation and purification of the functionalized polymer precursor .…”

“…Recently, the first, direct, in situ post‐ATRP chain‐end functionalization reaction was developed in our laboratories . For example, quantitative yields of α , ω ‐bis(oxazolyl)‐functionalized polystyrene were obtained by the in situ post‐ATRP chain‐end functionalization reaction of α ‐oxazolyl‐functionalized polystyrene with 4,5‐dihydro‐4,4‐dimethyl‐2‐[4‐(1‐phenylethenyl)phenyl]oxazole, without the need for isolation and purification of the functionalized polymer precursor . Similarly, the present article reports the preparation of α , ω ‐tetrakis(4‐aminophenyl)‐functionalized polystyrene ( 4 ) by the in situ post‐ATRP chain‐end functionalization reaction of 3 with 1 , without the need to isolate and purify the functionalized polymer precursor.…”