Degradative chain transfer in vinyl acetate polymerizations using toluene as solvent

Abstract

In this work, we propose that retardation in vinyl acetate polymerization rate in the presence of toluene is due to degradative chain transfer. The transfer constant to toluene (Ctrs) determined using the Mayo method is equal to 3.8 × 10-3, which is remarkably similar to the value calculated from the rate data, assuming degradative chain transfer (2.7 × 10-3). Simulations, including chain-length-dependent termination, were carried out to compare our degradative chain transfer model with experimental results. The conversion-time profiles showed excellent agreement between experiment and simulation. Good agreement was found for the Mn data as a function of conversion. The experimental and simulation data strongly support the postulate that degradative chain transfer is the dominant kinetic mechanism.© 2007 Wiley Periodicals, Inc.