A detailed mechanistic study of bulk MADIX of styrene and its chain extension

Devlaminck, Dries; Steenberge, Paul H. M. Van; Keer, Lies De; Reyniers, Marie-Françoise; D’hooge, Dagmar

doi:10.1039/c7py00961e

Cited by 23 publications

(39 citation statements)

References 106 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A first implicit assumption is the isothermicity of the experiments, which for active radical polymerization systems can be difficult to achieve. Diffusional limitations on conventional termination, that is, termination between macroradicals, which are known to be strong in MMA radical polymerization, have also been neglected . As conventional termination and disproportionation with SG1 are in direct competition (see Figure a), this simplification is expected to lead to a biased k td,SG1 parameter assessment.…”

Section: Resultsmentioning

confidence: 99%

“…Using literature data for the other reaction steps, parameter adjustment to monomer conversion (symbols in Figure ) and average chain length data (symbols in Figure ) allows to deduce that (details see Supporting Information)

k_{t d, S G 1} true(normalL {mol}^{- 1} s^{- 1} true) = 1.40 \cdot 10^{7} \exp (|, \frac{- 22.5 10^{3}}{R T})

in which R is the universal gas constant and T the temperature. The simulation results for the MMA conversion profiles, using Eq.…”

Section: Resultsmentioning

confidence: 99%

“…In this procedure, the initial number of initiator molecules is increased until convergence is obtained for the main polymerization characteristics. An additional convergence check for the average characteristics (e.g., monomer conversion, number average chain length, dispersity, and end‐group functionality) has been performed based on deterministic simulations, starting from previous code developments . For the TCLs covered in the present work (and aiming at a correct simulation of all polymer characteristics) the initial number of molecules needs to be as high as ca .…”

Section: Kinetic Modelmentioning

confidence: 99%

“…As MMA is in excess with respect to styrene, it is assumed that the apparent copolymerization termination is affected by diffusional limitations to the extent as for the homopolymerization of MMA. The empirical expression for MMA determined by Derboven et al is used. The contributions of the mode of termination, that is, disproportionation versus recombination, are calculated based on the nature of the terminal units of the participating radicals.…”

Section: Kinetic Modelmentioning

confidence: 99%

See 3 more Smart Citations

An evaluation of the impact of SG1 disproportionation and the addition of styrene in NMP of methyl methacrylate

et al. 2018

Self Cite

View full text Add to dashboard Cite

A kinetic modeling study is presented for batch nitroxide mediated polymerization (NMP) of methyl methacrylate (MMA; nitroxide: N‐tert‐butyl‐N‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)] (SG1)). Arrhenius parameters for SG1 disproportionation (A = 1.4 107 L mol−1 s−1; Ea = 23 kJ mol−1) are reported, based on homopolymerization data accounting for unavoidable temperature variations with increasing time, that is, nonisothermicity. For low targeted chain lengths (TCLs ≤ 300), this nonisothermicity is also relevant for NMP of MMA with a small amount of styrene. Parameter tuning to copolymerization data confirms a penultimate monomer unit effect for activation (sa2 = ka12/ka22=6.7; 363 K; 1: MMA; 2: styrene). To obtain, for a broad TCL range (up to 800), a dispersity well below 1.3 an initial styrene mass fraction of ca. 10% is required. An interpretation of the comonomer incorporation is performed by calculating the fractions of activation‐growth‐deactivation cycles with a given amount of monomer units and the copolymer composition distribution. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2545–2559, 2018

show abstract

Section: Resultsmentioning

confidence: 99%

k_{t d, S G 1} true(normalL {mol}^{- 1} s^{- 1} true) = 1.40 \cdot 10^{7} \exp (|, \frac{- 22.5 10^{3}}{R T})

in which R is the universal gas constant and T the temperature. The simulation results for the MMA conversion profiles, using Eq.…”

Section: Resultsmentioning

confidence: 99%

Section: Kinetic Modelmentioning

confidence: 99%

Section: Kinetic Modelmentioning

confidence: 99%

See 2 more Smart Citations

An evaluation of the impact of SG1 disproportionation and the addition of styrene in NMP of methyl methacrylate

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although many works about RAFT CTAs have recently been conducted, the complex processes and strict operation conditions of RAFT CTAs limit their wide applications. [4][5][6] For traditional CTAs, including mercaptans [7][8][9][10], alcohols [11], and halides [12], R X C Z Y Scheme 1. General chemical structure of the irreversible addition-fragmentation chain transfer (AFCT) agent.…”

Section: Introductionmentioning

confidence: 99%

Study on MMA and BA Emulsion Copolymerization Using 2,4-Diphenyl-4-methyl-1-pentene as the Irreversible Addition–Fragmentation Chain Transfer Agent

Zhang

et al. 2020

Polymers

View full text Add to dashboard Cite

As a chain transfer agent, 2,4-diphenyl-4-methyl-1-pentene (αMSD) was first introduced in the emulsion binary copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) based on an irreversible addition–fragmentation chain transfer (AFCT) mechanism. The effects of αMSD on molecular weight and its distribution, the degree of polymerization, polymerization rate, monomer conversion, particle size, and tensile properties of the formed latexes were systematically investigated. Its potential chain transfer mechanism was also explored according to the 1H NMR analysis. The results showed that the increase in the content of αMSD could lead to a decline in molecular weight, its distribution, and the degree of polymerization. The mass percentage of MMA in the synthesized polymers was also improved as the amounts of αMSD increased. The chain transfer coefficients of αMSD for MMA and BA were 0.62 and 0.47, respectively. The regulation mechanism of αMSD in the emulsion polymerization of acrylates was found to be consistent with Yasummasa’s theory. Additionally, monomer conversion decreased greatly to 47.3% when the concentration of αMSD was higher than 1 wt% due to the extremely low polymerization rate. Moreover, the polymerization rate was also decreased probably due to the desorption and lower reactivity of the regenerative radicals from αMSD. Finally, the tensile properties of the resulting polyacrylate films were significantly affected due to the presence of αMSD.

show abstract

Polymer Reaction Engineering

Saldívar‐Guerra¹

2019

Encyclopedia of Polymer Science and Technology

View full text Add to dashboard Cite

Polymer reaction engineering is a discipline that encompasses a set of principles and tools for the scaling up, design, analysis, control, troubleshooting, and optimization of industrial polymerization processes. Its tools are widely used in industry and are mainly taken from the fields of reaction kinetics, chemical reactor engineering, thermodynamics, physical chemistry, and applied mathematics. In this article, the basics to go from the polymerization reaction kinetics to reactor modeling are first introduced. Then, molecular weight distribution (MWDs) modeling tools are reviewed; these are classified and discussed as: analytical techniques, the method of moments, and numerical techniques for the complete MWD, covering both deterministic and stochastic methods. Next, the theoretical bases of copolymerization systems are discussed, including copolymerization models for copolymer composition and reactivity ratio estimation, to conclude with the discussion of the pseudo‐homopolymerization approach (or apparent rate constants method) for the modeling of the MWD in copolymerization systems. A section providing a general description of heterogeneous processes and their modeling is also included, covering the topics of population balance equations, suspension polymerization and emulsion polymerization. The article ends with a brief discussion of future perspectives in the field.

show abstract

A detailed mechanistic study of bulk MADIX of styrene and its chain extension

Abstract: By combining experimental and modeling tools, a detailed characterization study of MADIX properties becomes possible.

Cited by 23 publications

References 106 publications

An evaluation of the impact of SG1 disproportionation and the addition of styrene in NMP of methyl methacrylate

An evaluation of the impact of SG1 disproportionation and the addition of styrene in NMP of methyl methacrylate

Study on MMA and BA Emulsion Copolymerization Using 2,4-Diphenyl-4-methyl-1-pentene as the Irreversible Addition–Fragmentation Chain Transfer Agent

Polymer Reaction Engineering

Contact Info

Product

Resources

About