A thermistor method of determining the rate constant for the copolymerization of vinyl acetate and methyl methacrylate

The authors have tried to measure the overall rate for the copolymerization of vinyl acetate and methyl methacrylate at various monomer ratios and by use of a thermistor method to obtain the absolute rate of “crossed” chain termination. Although an assumed value was used for the heat of copolymerization to convert the rate of temperature rise into the rate of copolymerization, the agreement between the assumed and analytical values of this conversion factor was satisfactory. By substituting our results into Walling's equation, ϕ = 170 was obtained. Moreover, the use of the values of termination constants for vinyl acetate obtained previously and those for methyl methacrylate measured by Melville et al. led to a value of 1 × 1010 for the absolute rate of “crossed” chain termination at 24°C.