Emulsion Terpolymerization of St/MMA/BuA: III. Modeling of BuA Backbiting, Diffusion of Monomers and Polymers in the Particle, and BuA Induced Branching
In this work, the BuA backbiting and its kp-gel effect is included in a previous published model for the simulation of the emulsion terpolymerization of St/MMA/BuA. It is then possible to evaluate the branching of this terpolymer and the average diffusion of the monomers, polymers and polymer radicals. The diffusion is evaluated through the propagation and termination coefficients with a modification of the Schmoluchowski equation. On the other hand, it is also found that the BuA propagation coefficient depends on the fraction of BuA free volume XVf,BuA in the terpolymer and that the kind of model suitable for the simulation of the kp-gel effect is determined by the rate of polymerization Rp, the number of radicals in the particle per mol of monomers #R/n and the total diffusion of the polymer radicals in the particle nT DPR.
