C. McCormick, Gow-Sheng Chen, Brewer H. Hutchinson
Aug 1, 1982
Citations
0
Influential Citations
33
Citations
Journal
Journal of Applied Polymer Science
Abstract
Compositional analyses of random copolymers of acrylamide with sodium-2-sulfoethyl methacrylate and with sodium-2-acrylamido-2-methylpropane sulfonate have been performed utilizing elemental analysis, infrared spectroscopy, and C/sup 13/ NMR. Copolymers of acrylamide (AM) with sulfonated comonomers, especially sodium-2-acrylamido-2-methylpropane sulfonate (NaAMPS), offer hydrogen-bonding capability and polyelectrolyte behavior in aqueous solution-characteristics of special interest in enhanced oil recovery. A mathematical method involving nitrogen to sulfur ratios has been developed to eliminate errors which often arise from associated water in hydrophilic copolymers. The ratios of infrared absorbances at 1043 cm/sup -1/ and 1664 cm/sup -1/ were used to determine the composition of AM-NaAMPS copolymers; likewise, absorbance ratios at 1040 cm/sup -1/ and 3200 cm/sup -1/ were utilized for determination of the AM-NaSEM copolymer composition. Carbon-13 NMR spectra of the copolymers were obtained, and characteristic peaks were utilized to quantitate copolymer composition. The results obtained by elemental analyses, infrared spectroscopic studies, and NMR were in excellent agreement. These techniques are of great value for determining composition of hygroscopic copolymers which can crosslink or form strong intramolecular hydrogen bonds, often precluding further characterization.