Characterization of the Chemical Composition Distribution of Poly(n-butyl acrylate-stat-acrylic acid)s

A size exclusion chromatography (SEC)-gradient method is developed allowing poly(n-butyl acrylate-stat-acrylic acid)s to be separated with respect to content of acrylic acid over the complete composition range. After setting up the chromatographic method, samples that, according to the amounts of charged monomers, are expected to have identical chemical composition are compared. The chromatograms reveal differences in elution volume, which, by H-1 NMR spectroscopy, can be partially traced back to differences in polymer composition. In addition, samples of similar compositions prepared in different solvents exhibit differences in chemical composition distribution.