Dynamic Monte Carlo Simulation of Olefin Block Copolymers (OBCs) Produced via Chain‐Shuttling Polymerization: Effect of Kinetic Rate Constants on Chain Microstructure

Tongtummachat, Tiprawee; Anantawaraskul, Siripon; Soares, João B. P.

doi:10.1002/mren.201800021

Cited by 13 publications

(8 citation statements)

References 24 publications

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“…Since the discovery of chain shuttling polymerization − leading to the commercial production of diblock and multiblock polyolefin copolymers, , it has drawn a significant amount of research interest. − Olefin block copolymers have unique and advantaged properties rendering them useful for a number of applications. − For instance, ethylene/1-octene multiblock copolymers exhibit a unique balance of high melting point and flexibility compared to random copolymers with a similar comonomer content. − While simple metal alkyls are the most commonly used chain shuttling agents, effort is being made to design and synthesize more sophisticated chain shuttling agents (CSAs), such as dual-headed CSAs (DHCSAs), to access novel polymer architectures, such as telechelic and triblock polymers. Bickelhaupt et al reported the synthesis of difunctional cyclic zinc compounds using Rieke zinc and dibromoalkane .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Chain Shuttling Organometallic Compounds Capable of Producing Triblock Polyolefins

Sun¹,

Szuromi²,

Karjala³

et al. 2020

Macromolecules

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Organometallic oligomeric compounds with dual-headed structure R’-(M-R-) n M-R’ were developed enabling the synthesis of triblock polyolefins. The compounds comprise divalent linkers (R) derived from trivinylcyclohexane between two main group metals and norbornyl capping groups (R’). Due to the difference in steric hindrance, the chain transfer reaction in polymerization selectively involves the less hindered M–R bond, resulting in growth of polymer chains only from the R linker group with metals on both ends. The metal-terminated polymer can be further functionalized to form telechelic polymers or used in coordinative chain transfer polymerization to produce various triblock polyolefins. This paper presents the synthetic strategy and demonstrates the production of triblock polymers using the compounds in a scalable continuous solution polymerization process.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Chain Shuttling Organometallic Compounds Capable of Producing Triblock Polyolefins

Sun¹,

Szuromi²,

Karjala³

et al. 2020

Macromolecules

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“…In our previous publication, [20,22] the dynamic MC model was further extended to capture how the detailed microstructures OBC populations with a different number of blocks change during chain-shuttling polymerization in a semibatch reactor. However, the dynamic MC approach cannot apply directly to investigate the kinetics and microstructural evolution of OBCs during chain-shuttling polymerization 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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“…The lengths of the “hard” and “soft” segments are controlled by the kinetics of propagation and chain transfer at each catalyst center. Both high throughput experimentation (HTE) and kinetic modeling/simulation − approaches have been used to better understand chain-shuttling polymerization. However, without the active catalyst concentrations, the absolute rates of propagation and chain transfer cannot be determined .…”

Section: Introductionmentioning

confidence: 99%

Selective Quench-Labeling of the Hafnium-Pyridyl Amido-Catalyzed Polymerization of 1-Octene in the Presence of Trialkyl-Aluminum Chain-Transfer Reagents

2018

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The pyrenyl-isonitrile quench-labeling reagent selectively labels Hf-polymeryls over Al-alkyl species allowing for quantification of active site counts in polymerization. This selectivity also enables differentiation between catalyst-bound and Al-bound polymer molecular weight distributions (MWDs) via dual detection gel permeation chromatography (GPC) methods (UV-GPC and RI-GPC) in the Hf-pyridyl amidocatalyzed polymerization of 1-octene. Inhibition of polymerization is observed when using trialkyl aluminum chain-transfer agents with this catalyst system; for AlEt 3 , such inhibition can be eliminated by addition of the chain-transfer reagent after initiation of polymerization. Inhibition of polymerization cannot be eliminated when AlMe 3 is used in these polymerizations. With Al i Bu 3 , a larger ß-branched Al-alkyl, polymerization is not inhibited. For AlEt 3 , the propagation to exchange coefficient (k ex /k p ) was determined; compared with ZnEt 2 , chain transfer is approximately an order of magnitude slower. Through I 2 labeling and NMR analysis of polymer chain ends, the concentration of Al-polymeryls is quantified.

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Dynamic Monte Carlo Simulation of Olefin Block Copolymers (OBCs) Produced via Chain‐Shuttling Polymerization: Effect of Kinetic Rate Constants on Chain Microstructure

Cited by 13 publications

References 24 publications

Synthesis of Chain Shuttling Organometallic Compounds Capable of Producing Triblock Polyolefins

Synthesis of Chain Shuttling Organometallic Compounds Capable of Producing Triblock Polyolefins

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

Selective Quench-Labeling of the Hafnium-Pyridyl Amido-Catalyzed Polymerization of 1-Octene in the Presence of Trialkyl-Aluminum Chain-Transfer Reagents

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