NMR spectroscopy as basis for characterization of Pluronic (R) F108 and its derivatives

The hydroxyl end groups of Pluronic(R)F108 {a triblock copolymer surfactant of poly(ethylene glycol) and poly(propylene glycol) [PEG-PPG-PEG]) were mo dified into primary amine, sulfonic acid, and quaternary ammonium equivalen ts for use in affinity chromatography. NMR was used for monitoring the effi cacy of modifications on intermediaries and final products. The primary ami ne equivalents were prepared via conversion of the hydroxyl groups to a tos ylate, its displacement with an azide, followed by reduction to the primary amine. The sulfonic acid equivalents were prepared via hydroxyl group tosy lation, the displacement of tosylate with thiol, and its oxidation to sulfo nic acid. The conversion to trimethyl ammonium was achieved via hydroxyl gr oup tosylation, tosylate displacement by halide, and halide displacement wi th trimethylamine. (C) 2000 John Wiley & Sons, Inc.