STRUCTURE OF POLYMERIC QUATERNARY AMMONIUM-SALTS AND OF THE DERIVED COPOLYMERS

Structure of poly(dimethylaminoethyl methacrylate), polymeric quaternary ammonium salts derived from this polymer, and of graft copolymers of poly(dimethylaminoethyl methacrylate) with PMMA and PS was examined using X-ray photoelectron spectroscopy and high-resolution 1 H NMR. It was found that the degree of quaternization of polymeric quaternary ammonium salts may be evaluated by both methods, viz., by the ratio between the signals due to N-alkyl protons in ammonium and amine groups in 1 H NMR spectra and by the ratio between the intensities of the lines of Is levels of nitrogen of ammonium and amine groups in XPS spectra. For the polymers examined, 1s lines of carbon, oxygen, and nitrogen in XPS spectra were analyzed in detail. It was established that, when partially quaternized polymeric quaternary ammonium salts interact with potassium persulfate, some amine groups of the polymer are oxidized, whereas potassium persulfate decomposes and forms sulfate anions, which almost completely replace monovalent counterions.