Abstract
Esters of 2-bromo-2-methylpropanoate of poly(oxyalkylene) polymers such as poly(ethylene glycol) or α-methyl poly(ethylene glycol) were prepared in high yields and characterized by spectroscopic and chromatographic methods (NMR, FT-IR, mass spectroscopy and SEC). The halogen chain-end group in the poly(oxyalkylene) bromine-terminated esters were characterized by MALDI-TOF MS. The effect of the solvents (methanol or tetrahydrofuran) and the cationic agents such as silver trifluoroacetate (AgTFA), silver trifluoromethanesulfonate (AgTFS) and sodium trifluoroacetate (NaTFA) on the mass spectra was studied. Analysis of the mass spectra demonstrated that the analyte was transformed to unsaturated (elimination), alkoxy or hydroxyl end groups (substitution) molecules when silver cationic agents were used, these results were also supported by 1H NMR study. When sodium salt was used as a cationic agent, well-defined bromine-terminated macromolecules were successfully determined through MALDI-TOF MS. Well characterized esters of 2-bromo-2-methylpropanoate of poly(oxyalkylene) polymers could be used as ATRP macroinitiators for the synthesis of a variety of polymeric architectures of interest as drug delivery bioconjugates.
Published Version
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