Kinetics of MMA Atom Transfer Radical Polymerization Initiated by Reducing Agent in Stirred Batch Emulsion Reactor

Abstract

only a limited number of studies were done in aqueous media, [4] even though, conducting polymerization in dispersed media is more convenient for economic and environmental reasons, and industrial settings. [5][6][7] However, ATRP behavior in emulsion medium may present few concerns including wide particle size distribution, loss of control of the polymerization, and low initiation efficiency. [8] A number of ATRP studies [5,6,9] have applied new initiation techniques called activators generated by electron transfer (AGET) which not only demands a relatively low amount of catalyst complex but can also use ecofriendly reducing agents such as vitamin C or sugar. Besides, the AGET ATRP technique can be performed in emulsion medium by incorporating stable and oxidative copper (CuBr 2 ) complex in the initiation step. It is important to highlight that an in-depth understanding of chemical kinetic features of ATRP in emulsion systems is not quite well documented in open literature. In fact, ATRP is still largely unstudied in dispersed systems. [6] Oh et al. [7] conducted a very interesting review of controlled radical polymerization (CRP) techniques in emulsion and dispersion systems.At theoretical level, several studies have reported different mathematical methods to understand the behavior of ATRP in dispersed medium. [10][11][12][13][14][15][16][17][18][19] Assumptions were made in order to simplify the ATRP reaction mechanism. For instance, these ATRP systems were conducted in miniemulsion or dispersion mediums and have polymer particle diameters from 35 to 70 nm with low conversion. [19,20] It is clear that ATRP is different from free radical polymerization in a few aspects such as thermodynamic and chemical equilibriums of the system. Moreover, deactivating species along with propagating radicals were assumed to transfer radicals between monomer droplets and polymerizing particles. Besides, there is a lack of a sufficient experimental data over a reasonable range of reaction conditions in order to gain a better understanding of ATRP kinetic mechanism in emulsion medium. For instance, Peng et al. [21] carried out an experimental investigation of n-butyl methacrylate (BMA) ATRP in emulsion polymerization. They investigated the effects of several factors including the Ab initio emulsion atom transfer radical polymerization (ATRP) differs from regular emulsion polymerization because the kinetic and thermodynamic aspects of each process are very unlikely alike. This paper presents a kinetic analysis of activator generated by electron transfer (AGET) ATRP of methyl methacrylate (MMA) in a stirred emulsion reactor. The focus of the study is to assess the variation of the monomer content in the organic phase and the rate polymerization for different reaction temperatures, as well as the impact of surfactant content and stirring speed on latex stability. Poly(methyl methacrylate) (PMMA) polymer samples are analyzed by means of gravimetry, dynamic light scattering, gel permeation chromatography, and HNMR techniques to dete...

Experimental Study of AGET ATRP of MMA and BMA Homopolymerizations in Emulsion Batch Reactor

“…The contents of this chapter are adopted from the manuscript published in Journal of Macromolecular Reaction Engineering; DOI: 10.1002/mren.202000052. (Awad et al 2021).…”

“…particular system in open literature, but still insufficient to develop appropriate mechanistic models (Awad et al, 2021). In this case, empirical models developed from the use of systematic statistical design of experiments are recommended in order to collect more data about this complex system and predict the influence of key variables over the process.…”

Experimental Study of AGET ATRP of MMA and BMA Homopolymerizations in Emulsion Batch Reactor

“…The contents of this chapter are adopted from the manuscript published in Journal of Macromolecular Reaction Engineering; DOI: 10.1002/mren.202000052. (Awad et al 2021).…”

Influence of redox initiator component ratios on the emulsion copolymerisation of vinyl acetate and neodecanoic acid vinyl ester

“…of methyl methacrylate, styrene and butyl acrylate) can be lowered to 40 C, without signicantly affecting product properties, such as particle size or conversion. [22][23][24] A further decrease of the process initiation temperature down to 30 C and room temperature was achieved in the production of polyaniline. 25,26 Reducing the initiation temperature without altering the product contributes positively to process intensication and process safety.…”