Mathematical model for the bulk polymerization of styrene chemically initiated by sequential and total decomposition of the trifunctional initiator diethyl ketone triperoxide

Abstract

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 study focused on temperatures of 150 to 200 C, considering chemical initiation by both sequential and total decomposition reactions. The experimental work consisted of a series of isothermal batch polymerizations at higher temperatures, 150 and 200 C, with an initiator concentration of 0.01 mol/L. The mathematical model is based on a kinetic mechanism that includes thermal and chemical initiation (both sequential and total decomposition reactions), propagation, transfer to monomer, termination by combination and re-initiation reactions. Experimental and theoretical results show that the decomposition mechanism of the initiator is modified by the reaction temperature and can be modeled as a set of two parallel reactions with different temperature dependences. The developed mathematical model simulates the bulk polymerization of St in the presence of DEKTP for a wide temperature range (120-200 C). It was found that due to these two decomposition mechanisms, the system may behave as a "dead-end" polymerization system above a certain temperature, yielding low molecular weights and a limiting conversion value. Simulation results indicate the value of this temperature to be about 185 C. POLYM. ENG. SCI., 55:145-155, 2015.

Bulk Polymerization of Styrene using Multifunctional Initiators in a Batch Reactor: A Comprehensive Mathematical Model

“…The experimental work consisted on the synthesis and characterization of the organic peroxide PDP and isothermal batch bulk polymerizations of St using the multifunctional initiators PDP and L331 at 0.01 mol/L. The experimental data for bulk polymerization of styrene using the trifunctional cyclic initiator DEKTP were taken from our previous work (Berkenwald et al 2013). The selected polymerization temperatures are such that initiator decomposition is mostly sequential (Cerna et al 2002; Casteñeda Facio 2007).…”

“…With respect to initiator structure, it was observed that the use of cyclic multifunctional initiators (e.g..: triperoxide cyclohexanone (CHTP), diethylketone triperoxide (DEKTP), acetone triperoxide (ATP), cyclohexanone diperoxide (CHDP) and pinacolone diperoxide (PDP)) in polymerization reactions represents a promising alternative (Sheng et al 2004;Castañeda Facio 2007;Berkenwald et al 2013;Berkenwald et al 2015). Sheng et al (2004) experimentally studied the use of the cyclic trifunctional initiator 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane in the bulk polymerization of St.…”

“…The obtained PS had remaining "O-O" bonds in the molecular chains. In Berkenwald et al (2013), the use of diethyl ketone triperoxide (DEKTP), a cyclic trifunctional peroxide initiator, in the bulk polymerization of St was experimentally and theoretically studied. A mathematical model was developed to predict the evolution of the reacting species concentration, monomer conversion, and detailed polymer molecular structure.…”

Experimental and theoretical study of the use of multifunctional initiators in the high impact polystyrene bulk process

“…The medium cis ‐PB was provided by Dynastol Elastómeros S.A de C.V., México ( ). Cyclic initiators DEKTP and PDP were synthesized and characterized as in our previous work .…”

Explicit stochastic modeling of termination chain length dependencies for all disparate radical pairs in single phase free radical induced grafting

“…Detailed FRIG kinetic modeling studies differentiating between all apparent termination chain length dependencies are scarce. As shown in Table 1, most studies are deterministic and focus on the modeling of average characteristics applying average-based termination models, specifically the wp -like models [53][54][55][56][57][58][59][60][61][62][63][64][65][66][67]; some models are even intrinsic [68][69][70][71][72][73]. One of the most detailed deterministic models has been developed by Estenoz and Meira [68] considering isothermal solution FRIG of PB with St, able to acceptably match experimental data for monomer conversion, average molar mass, and grafting efficiency.…”