Solution of the recursion equations for emulsion polymerisation kinetics in the non-stationary state
Abstract
The recursion equations which describe the kinetics of emulsion polymerisation in the nonstationary state have been solved by a numerical method. Radical–radical reactions within the particles, radical desorption, particle growth, re-adsorption of desorbed radicals and decay of the radical generator are included in the kinetic scheme. Unlike previous treatments, this new procedure allows for the simultaneous ooccurrence of these events even though the net rate of radical transfer to the particles and the particle growth rate are time-dependent.
It is shown that failure to include re-adsorption of desorbed radicals and radical–radical reactions within the particles may lead to serious error in the estimation of radical populations. The initial value of the particle volume has a limited effect on the kinetics but particle growth lessens the decline in radical populations which occurs in the later stages of the process. The value of the radical desorption coefficient has a distinct effect on the dynamic behaviour of the system.