Computer simulation of radical polymerization kinetics under nonisothermal conditions in a perfect-mixing reactor

The radical polymerization of vinyl acetate and styrene in a perfect-mixing reactor was studied by computer simulation disregarding the influence of conversion on the rate constants of elementary reactions. Benzoyl peroxide and dicyclohexylperoxydicarbonate, which have identical activation energies of degradation but preexponential factors differing by two orders of magnitude, were chosen as initiators. The starting initiator concentrations, the initial reactor temperature, and the reactor heat-transfer coefficient determining the heat withdrawal rate were varied in the simulation. The heating of the reactor system in the course of reaction or process; the heat evolution rate; and the current concentrations of monomer, initiator, and chain-carrier radicals were calculated. The treatment of the obtained data in terms of N.N. Semenov's thermal explosion theory revealed some features of kinetic behavior that might be expected for radical polymerization under nonisothermal conditions. Practical recommendations for selection of an appropriate initiator and safe execution of polymerization processes were made.