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The kinetic developments of the free-radical bulk polymerization of styrene in the presence of recycled rubber tire particles are studied by isothermal differential scanning calorimetry (DSC). Two different chemical initiators, namely benzoyl peroxide (BPO) and 2,2'-Azobis(2methylbutyronitrile) (AMBN), are tested in a series of variable-composition experiments, under three different polymerization temperatures, in order to selectively address the role of the different species on the evolution of the polymerization reaction. The variation of the overall effective kinetic rate constant and activation energy of the polymerization are also calculated to quantify the effect of the addition of the particulate filler. The results of the study demonstrate that the combination of the peroxide initiator agent with a composition of the reacting mixture in the order of 30 mass%, in terms of the rubber tire particles, results in a significant deviation of the evolution of the rate of polymerization and monomer conversion, with respect to that of the pure homopolymerization system in the absence of tire particles. The observed phenomena are consistent with previous studies reported in the literature and are mainly attributed to the chemical interactions taking place between the initiator agent and additives of the formulation of the tire particles.

This paper deals with the development of a dynamic real-time optimization (D-RTO) methodology and its experimental use in optimal operation of a batch reactor where polymer grafting reactions take place. It combines a constrained dynamic optimization method with a moving horizon state estimator within closed-loop control. The objective is to determine the online reactor temperature profile that minimizes the batch final time while meeting terminal constraints on the overall conversion rate and grafting efficiency. The methodology is first implemented in open-loop control in order to set up the experimental procedure and at the same time to assess the model accuracy. It is then implemented in closed-loop control, and the resulting computed and measured optimal profiles of temperature, monomer conversion rate, and grafting efficiency exhibit very good agreement and show also that the terminal constraints are satisfied.