EXPERIMENTAL AND THEORETICAL STUDY OF THE BULK POLYMERIZATION OF STYRENE USING THE SYMMETRICAL CYCLIC TRIFUNCTIONAL INITIATIOR DIETHYL KETONE TRIPEROXIDE (DEKTP)

摘要

This work experimentally and theoretically investigates the use of the symmetrical cyclic trifunctional initiator diethyl ketone triperoxide (DEKTP) in the bulk polymerization of styrene (St). The experimental work consisted on a series of isothermal batch polymerizations at different temperatures, 120 and 130oC, with different initiator concentrations: 0. 005, 0. 01 and 0. 02 mol/L. A mathematical model was developed in order to predict the evolution of the reacting chemical species and the produced molecular weights distributions (MWDs). The kinetic model includes chemical and thermal initiation, propagation, transfer to the monomer, termination by combination and reinitiation reactions. Simulation results predict the concentration of di- and monoradicals as well as polymeric chains, characterized by the number of undecomposed peroxide sites. Experimental results show that, at reaction temperatures of 120 - 130oC, DEKTP initiation produces an increase in polymerization rates and average molecular weights, depending on the initiator concentration, due to sequential decomposition of the initiator molecule. The optimal DEKTP concentration for St bulk polymerization is found to be 0.01 mol/L. The mathematical model was adjusted and validated using the experimental data. Theoretical predictions are in excellent agreement with the experimental results.