Critically Evaluated Rate Coefficients in Radical Polymerization-8. Propagation Rate Coefficients for Vinyl Acetate in Bulk

Abstract

Propagation rate coefficient values, k(p), reported by several groups for radical polymerization of bulk vinyl acetate are critically evaluated. All data are obtained by the combination of pulsed-laser polymerization and subsequent polymer analysis by size exclusion chromatography, as recommended by the IUPAC Working Party on Modeling of Polymerization Kinetics and Processes. Although a small (approximate to 15%) increase in k(p) is observed as laser pulse repetition rate is increased from low (25-100 Hz) to high (300-500 Hz) values, all of the data fulfill the required consistency criteria and thus are combined into a benchmark set covering the temperature range of 5-70 degrees C. The data are fitted well by an Arrhenius relation resulting in a pre-exponential factor of 1.35 x 10(7) L mol(-1) s(-1) and an activation energy of 20.4 kJ mol(-1), with 95% confidence ellipsoids for the parameters also presented.