Novel Olefin Block Copolymers through Chain‐Shuttling Polymerization

Zintl, Manuela; Rieger, Bernhard

doi:10.1002/anie.200602889

Cited by 66 publications

(48 citation statements)

References 26 publications

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“…One catalyst has low comonomer reactivity ratio and produces high‐crystallinity blocks ( hard‐blocks ), while the other catalyst has high comonomer reactivity ratio and makes low‐crystallinity blocks ( soft‐blocks ). The CSA is the special component because it shuttles living polymer chains between the two catalysts, making chains with alternating hard and soft blocks . OBCs have higher heat and abrasion resistances, and better processability than conventional polyolefin elastomers …”

Section: Introductionmentioning

confidence: 99%

Understanding the Formation of Linear Olefin Block Copolymers with Dynamic Monte Carlo Simulation

Tongtummachat

Anantawaraskul

Soares

2016

Macro Reaction Engineering

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low comonomer reactivity ratio and produces high-crystallinity blocks (hard-blocks), while the other catalyst has high comonomer reactivity ratio and makes low-crystallinity blocks (soft-blocks). The CSA is the special component because it shuttles living polymer chains between the two catalysts, making chains with alternating hard and soft blocks. [1][2][3][4][5][6][7] OBCs have higher heat and abrasion resistances, and better processability than conventional polyolefin elastomers. [8][9][10][11] Because OBC may have many blocks, mathematical models are needed to quantify how polymerization conditions affect their microstructures. A detailed mathematical model describes how the complex OBC microstructure evolves during polymerization, providing useful insights on how to control these microstructures. Models for chain-shuttling polymerization in continuous stirred-tank reactors (CSTRs) were first developed using the method of moments to describe polymerization kinetics and average chain microstructures. [12,13] Because this approach cannot generate detailed microstructural distributions, Monte Carlo (MC) models were later developed for OBCs made in CSTRs operated at steadystate. [14][15][16] Subsequently, Mohammadi et al. developed Chain-shuttling polymerization with dual catalysts has introduced a new class of polyolefins called olefin block copolymers (OBCs). A dynamic Monte Carlo model to describe the kinetics of chain-shuttling copolymerization in a semi-batch reactor is developed, and used it to study how the microstructure of OBCs with different numbers of blocks per chain evolves during polymerization. The model also describes how chain-shuttling rate constants and concentration of chain-shuttling agent affect populations of OBCs with different numbers of blocks per chain. These model predictions are useful to make OBCs with precisely designed microstructures.

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Section: Introductionmentioning

confidence: 99%

Understanding the Formation of Linear Olefin Block Copolymers with Dynamic Monte Carlo Simulation

Tongtummachat

Anantawaraskul

Soares

2016

Macro Reaction Engineering

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“…Synthesizing polymers with exactly tunable molecular weight and narrow molecular weight distribution (MWD) is the goal on which unremitting effort has been focused. Chain shuttling polymerization1–4 is a newly developed protocol that expands the architecture control in preparing olefin block copolymer (OBC). Two catalysts with distinct comonomer affinities and a chain transfer agent called “chain shuttling agent” (CSA) have been used in chain shuttling polymerization.…”

Section: Introductionmentioning

confidence: 99%

Preparation of highcis‐1,4 polyisoprene with narrow molecular weight distribution via coordinative chain transfer polymerization

Fan

Bai

Cai

et al. 2010

J. Polym. Sci. A Polym. Chem.

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High cis‐1,4 polyisoprene with narrow molecular weight distribution has been prepared via coordinative chain transfer polymerization (CCTP) using a homogeneous rare earth catalyst composed of neodymium versatate (Nd(vers)3), dimethyldichlorosilane (Me2SiCl2), and diisobutylaluminum hydride (Al(i‐Bu)2H) which has strong chain transfer affinity is used as both cocatalyst and chain transfer agent (CTA). Differentiating from the typical chain shuttling polymerization where dual‐catalysts/CSA system has been used, one catalyst/CTA system is used in this work, and the growing chain swapping between the identical active sites leads to the formation of high cis‐1,4 polyisoprene with narrowly distributed molecular weight. Sequential polymerization proves that irreversible chain termination reactions are negligible. Much smaller molecular weight of polymer obtained than that of stoichiometrically calculated illuminates that, differentiating from the typical living polymerization, several polymer chains can be produced by one neodymium atom. The effectiveness of Al(i‐Bu)2H as a CTA is further testified by much broad molecular weight distribution of polymer when triisobutylaluminum (Al(i‐Bu)3), a much weaker chain transfer agent, is used as cocatalyst instead of Al(i‐Bu)2H. Finally, CCTP polymerization mechanism is validated by continuously decreased Mw/Mn value of polymer when increasing concentration of Al(i‐Bu)2H extra added in the Nd(ver)3/Me2SiCl2/Al(i‐Bu)3 catalyst system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

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“…1 However, only a limited number of monomers and reaction sequences are amenable to living anionic polymerization, which may be prohibitively expensive. 2 To overcome these limitations, researchers have developed a variety of alternative synthetic strategies, such as chain shuttling polymerizations, 3,4 ring-opening metathesis polymerizations, 5 and controlled radical polymerizations. [6][7][8][9] While these methods increase the number of monomers that can be incorporated into block copolymers, possibly at lower costs, block PDIs greater than 1.2 often result.…”

Section: Introductionmentioning

confidence: 99%

Polydispersity effects in poly(isoprene-b-styrene-b-ethylene oxide) triblock terpolymers

Meuler

Ellison

Qin

et al. 2009

The Journal of Chemical Physics

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Four hydroxyl-terminated poly͑isoprene-b-styrene͒ diblock copolymers with comparable molecular weights and compositions ͑equivalent volume fractions of polyisoprene and polystyrene͒ but different polystyrene block polydispersity indices ͑M w / M n = 1.06, 1.16, 1.31, 1.44͒ were synthesized by anionic polymerization using either sec-butyllithium or the functional organolithium 3-triisopropylsilyloxy-1-propyllithium. Poly͑ethylene oxide͒ ͑PEO͒ blocks were grown from the end of each of these parent diblocks to yield four series of poly͑isoprene-b-styrene-b-ethylene oxide͒ ͑ISO͒ triblock terpolymers that were used to interrogate the effects of varying the polydispersity of the middle bridged polystyrene block. In addition to the neat triblock samples, 13 multicomponent blends were prepared at four different compositions from the ISO materials containing a polystyrene segment with M w / M n = 1.06; these blends were used to probe the effects of increasing the polydispersity of the terminal PEO block. The melt-phase behavior of all samples was characterized using small-angle X-ray scattering and dynamic mechanical spectroscopy. Numerous polydispersity-driven morphological transitions are reported, including transitions from lamellae to core-shell gyroid, from core-shell gyroid to hexagonally packed cylinders, and from network morphologies ͓either O 70 ͑the orthorhombic Fddd network͒ or core-shell gyroid͔ to lamellae. Domain periodicities and order-disorder transition temperatures also vary with block polydispersities. Self-consistent field theory calculations were performed to supplement the experimental investigations and help elucidate the molecular factors underlying the polydispersity effects. The consequences of varying the polydispersity of the terminal PEO block are comparable to the polydispersity effects previously reported in AB diblock copolymers. Namely, domain periodicities increase with increasing polydispersity and domain interfaces tend to curve toward polydisperse blocks. The changes in phase behavior that are associated with variations in the polydispersity of the middle bridged polystyrene block, however, are not analogous to those reported in AB diblock copolymers, as increases in this middle block polydispersity are not always accompanied by ͑i͒ increased domain periodicities and ͑ii͒ a tendency for domain interfaces to curve toward the polydisperse domain. These results highlight the utility of polydispersity as a tool to tune the phase behavior of ABC block terpolymers.

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Novel Olefin Block Copolymers through Chain‐Shuttling Polymerization

Cited by 66 publications

References 26 publications

Understanding the Formation of Linear Olefin Block Copolymers with Dynamic Monte Carlo Simulation

Understanding the Formation of Linear Olefin Block Copolymers with Dynamic Monte Carlo Simulation

Preparation of highcis‐1,4 polyisoprene with narrow molecular weight distribution via coordinative chain transfer polymerization

Polydispersity effects in poly(isoprene-b-styrene-b-ethylene oxide) triblock terpolymers

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