ESTIMATION OF THE REACTIVITY RATIOS IN THE CO-POLYMERIZATION OF ACRYLIC-ACID AND ACRYLAMIDE FROM COMPOSITION-CONVERSION MEASUREMENTS BY AN IMPROVED NON-LINEAR LEAST-SQUARES METHOD

A new method is developed to estimate the reactivity ratios from composition–conversion data based on nonlinear regression. Previously published experimental data for the copolymerization of acrylic acid and acrylamide are analyzed by the new method and the results compared to those reported by the original investigators. Composition–conversion data were collected for this copolymerization system at intermediate conversion levels and over a limited range of compositions. Values for the reactivity ratios at 40°C were obtained from these data by the new algorithm and compared to the literature values. Copyright © 1979 John Wiley & Sons, Inc.