NONSTATIONARY STATES IN FREE-RADICAL POLYMERIZATIONS WITH SIZE-DEPENDENT TERMINATION STUDIES BY THE GROUP-TERMINATION PROCEDURE .39 FURTHER CONSIDERATION OF AFTER-EFFECTS AND PRE-EFFECTS AND EVALUATION OF ABSOLUTE COEFFICIENTS

In earlier studies of the kinetic quantities in non-stationary stages of non-classical free-radical polymerization a relation between the total pre- and after-effects (DELTAM(pre), DELTAM(aft), respectively) and the rate coefficients k(p)k(to) was proposed. This arose from the results of numerical computation. Further work shows that the relation is derivable from the basic kinetic equations and is therefore of general validity. We have been able to formulate a new quantity LAMBDA which is a function of the ratio of the final and initial rates of initiation (I2, I1, respectively) (not the individual values) and is independent of the rate coefficients. It is useful for the evaluation of absolute rate coefficients in non-classical systems and the procedure involved is explained. Values of LAMBDA are presented in the form of contour lines on a beta VS I2/I1 diagram. A method for calculating LAMBDA based on empirical relations between radical concentrations and mean radical sizes is outlined. A special case has been found [beta = 0.25, see equation (1)] for which analytical solutions can be obtained. The derived expressions for radical concentrations and DELTAM(pre) and DELTAM(aft) are presented. As in earlier papers in this series concerned with non-stationary states we assume chain transfer to be insignificant.