Characterization of styrene/methacrylic acid copolymers by 2D-NMR spectroscopy

Styrene/methacrylic acid copolymers were prepared by free-radical photopolymerization using the uranyl nitrate ion as the initiator. The copolymer composition was determined from ¹H-NMR spectroscopy. The comonomer reactivity ratios determined using Kelen Tudos and nonlinear error in variable methods (EVM) are r_m = 0.61 ± 0.05 and r_s = 0.14± 0.07. The broad and overlapping ¹H-NMR spectrum was assigned using the help of 2D TOCSY and NOESY experiments. These methods were used to ascertain the various geminal, vicinal, and spatial couplings between the protons. The methyl and methine protons also show configurational and compositional sensitivity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2444–2453, 2001