A Simple Monte Carlo Method for Modeling Arborescent Polymer Production in Continuous Stirred Tank Reactor

Zhao, Yutian R.; Buren, Bradley D.; Puskás, Judit E.; McAuley, Kimberley B.

doi:10.1002/mren.201800020

Cited by 9 publications

(6 citation statements)

References 46 publications

(103 reference statements)

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“…More recently, Zhao et at. [24] proposed a new dynamic MC approach to simulate arborescent polyisobutylene production via self-condensing vinyl copolymerization in an unsteadystate CSTR operation. This model provides useful information on dynamic changes in molecular weight and MWD of polyisobutylene produced in CSTR.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Monte Carlo Simulation for Chain‐Shuttling Polymerization of Olefin Block Copolymers in Continuous Stirred‐Tank Reactor

Tongtummachat

Ma‐In

Anantawaraskul

et al. 2020

Macro Reaction Engineering

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consists of two catalysts with different α-olefin reactivity ratios and a chain shuttling agent (CSA). One of the catalysts with good α-olefin incorporation produces lowcrystallinity segments (soft blocks), while the other with poor α-olefin incorporation produces high-crystallinity segments (hard blocks). The CSA is added to "shuttle" growing chains between two catalysts, leading to statistical multiblock chain microstructures of OBCs. Due to their unique multiblock chain micro structures, OBCs have been reported to have several advantages, such as better end-use properties and processability, when compared to conventional polyolefin elastomers. [8-11] Since Zhang et al. [12] proposed the reaction mechanism, kinetic parameters, and reaction conditions for ethylene/1octene chain-shuttling polymerization, several mathematical models have been developed. [12-22] The model based on the method of moments for ethylene/1-octene chain-shuttling polymerization in continuous stirred-tank reactor (CSTR) was developed for the first time by Zhang et al. [12,13] Their model provides useful information on how the average microstructural properties of OBCs (i.e., average molecular weight, average copolymer composition, and average soft and hard block structures) vary with polymerization conditions. Unfortunately, this approach provides only the average microstructural properties of OBCs. To overcome the limitation of the previous approach, Anantawaraskul et al. [14-16] developed the static Monte Carlo (MC) model to provide detailed microstructural distribution of OBCs at the steady-state. The authors used the MC model to investigate the effect of polymerization parameters (i.e., chain-shuttling probability, propagation probability, transfer probability, catalyst ratio) on the chemical composition distribution (CCD), ethylene sequence distribution (ESD), and distribution of the number of blocks per chain. This approach, however, cannot describe the kinetics and microstructural evolution of OBCs. Recently, a dynamic MC model was developed to describe kinetics and microstructural evolution of OBCs during chainshuttling polymerization in a semibatch reactor. [17-22] Mohammadi et al. [17] introduced a dynamic MC model to discuss kinetics of chain-shuttling polymerization using dual catalysts based on the kinetics of coordinative chain transfer poly merization (a combining of living coordination poly merization with an A dynamic Monte Carlo model coupling with residence time distribution is developed to simulate chain microstructures of olefin block copolymers (OBCs) produced with the chain-shuttling polymerization in a continuous stirred-tank reactor (CSTR). The simulated results provide information on how polymer chain microstructures (i.e., average molecular weight, average comonomer content, and microstructural distributions) evolve in a CSTR system and show a good agreement with previously reported theoretical and experimental results. The model is also used to investigate effect of reaction conditions (i.e., catalyst feed compo...

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Section: Introductionmentioning

confidence: 99%

Dynamic Monte Carlo Simulation for Chain‐Shuttling Polymerization of Olefin Block Copolymers in Continuous Stirred‐Tank Reactor

Tongtummachat

Ma‐In

Anantawaraskul

et al. 2020

Macro Reaction Engineering

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“…Similar behavior was observed also for the step polymerization of AB 2 type monomer, as well as for the free‐radical polymerization with chain transfer to polymer, conducted in a CSTR, and such behavior was rationalized by the formation of scale‐free power‐law distribution for the large MW tail. A Monte Carlo (MC) simulation method to determine the full MWD profile for SCVCP in a CSTR was proposed recently by using the Gillespie MC algorithm . In this method, the simulation is conducted on the number basis by considering a very small reactor volume.…”

Section: Introductionmentioning

confidence: 99%

Hyperbranched Polymers Formed Through Self‐Condensing Vinyl Polymerization in a Continuous Stirred‐Tank Reactor (CSTR): 1. Molecular Weight Distribution

Tobita

2018

Macro Theory & Simulations

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A new Monte Carlo simulation algorithm, based on the random sampling technique, is proposed for the self-condensing vinyl polymerization conducted in a continuous stirred-tank reactor. In order to highlight the most fundamental aspects of the reaction system, the kinetic rate constants are assumed to be constant, and the size and structure dependence is neglected. With this ideal model, the high molecular weight (MW) tail of the weight fraction distribution W(P) is shown to follow the power law, W(P) ∝ P −α . The power exponent is represented by α = 1/(ηξ) for ξ < 1/(2η), where ξ and η are defined in the text. For ξ ≥ 1/(2η), the weight-average MW cannot reach the steady state because of the power exponent with α ≤ 2.The reactivity ratio, r, is defined by(3)

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“…Note that in the present MC simulation method, the polymer molecules were selected on a weight basis randomly from the final product. The branched architecture of the large sized polymer molecules could be estimated effectively, because larger polymer molecules have a better chance of being selected, compared with the MC simulation conducted on a number basis . The HB polymer molecules whose degree of polymerization P was larger than 50 were collected to clarify the properties of large HB polymers.…”

Section: Methodsmentioning

confidence: 99%

“…The branched architecture of the large sized poly mer molecules could be estimated effectively, because larger polymer molecules have a better chance of being selected, compared with the MC simulation conducted on a number basis. [13] The HB polymer molecules whose degree of polymerization P was larger than 50 were collected to clarify the properties of large HB polymers. The total of 5 × 10 3 or more polymer molecules with P > 50 were analyzed to determine statistically valid estimates.…”

Section: Methodsmentioning

confidence: 99%

Detailed Structural Analysis of the Hyperbranched Polymers Formed in Self‐Condensing Vinyl Polymerization

Tobita

2019

Macro Theory & Simulations

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Monte Carlo simulation is applied to investigate the effect of reactor types on the formed hyperbranched architecture. When a continuous stirred‐tank reactor (CSTR) is used for the synthesis, the number of units incorporated into the largest cluster of dendritic units inside the hyperbranched polymer increases with molecular weight, while it does not increase in batch polymerization. The largest dendritic cluster formed in a CSTR consists of the monomeric units whose average residence time is large, while the average residence time of the singly connected peripheral units is small. The maximum span length as well as the mean‐square radius of gyration of the high molecular weight polymer is much smaller for the polymers synthesized in a CSTR, compared with batch polymerization. A universal relationship between the mean‐square radius of gyration and the maximum span length is found, which is valid for both batch and CSTR.

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A Simple Monte Carlo Method for Modeling Arborescent Polymer Production in Continuous Stirred Tank Reactor

Cited by 9 publications

References 46 publications

Dynamic Monte Carlo Simulation for Chain‐Shuttling Polymerization of Olefin Block Copolymers in Continuous Stirred‐Tank Reactor

Dynamic Monte Carlo Simulation for Chain‐Shuttling Polymerization of Olefin Block Copolymers in Continuous Stirred‐Tank Reactor

Hyperbranched Polymers Formed Through Self‐Condensing Vinyl Polymerization in a Continuous Stirred‐Tank Reactor (CSTR): 1. Molecular Weight Distribution

Detailed Structural Analysis of the Hyperbranched Polymers Formed in Self‐Condensing Vinyl Polymerization

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