INVESTIGATION OF POLYMERIZATION KINETICS AT HIGH CONVERSION

The polymerization of methyl-methacrylate was investigated in the presence of different initiators and retarders. For processing the measured data a calculation method was worked out on the basis of regression analysis. The results have shown that at high conversion only the rate constant of the chain termination reaction decreases, those of the initiation and chain propagation reactions do not change. Correlation was found between the rate constant of the chain termination reaction and the viscosity of the monomeric- polymeric system. It was shown that the rate of reaction between the macroradical and the retarder molecule is the same at the beginning stage of polymerization and at high conversions. The amount of retardation is determined by the μk5z product also at high conversions. Calculations were made for controlling the exact suitability of the Cardenas- O'Driscoll model for describing the change of polymerization rate depending on the con- version. Our calculations pointed out that the model does not give an exact correlation between the change of polymerization rate and the conversion