Well-defined cyclic polymer synthesis <i>via</i> an efficient etherification-based bimolecular ring-closure strategy

Sharma, Sandeep Kumar; Ντέτσικας, Κωνσταντίνος; Ladelta, Viko; Bhaumik, Saibal; Hadjichristidis, Nikos

doi:10.1039/d1py01337h

Cited by 7 publications

(7 citation statements)

References 46 publications

(53 reference statements)

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“…In general, the end-capping of the living chain end with EO followed by the addition of methanol results in OH-functionalized polymers with a high degree of functionalization (>99%). 55,56 PS-OH and PI-OH macroinitiators with three different targeted molecular weights: 5, 10, and 20 kg mol −1 were prepared. Their molecular characteristics are presented in Table S1 of the Supporting Information.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Non-Covalent PS–SC–PI Triblock Terpolymers via Polylactide Stereocomplexation: Synthesis and Thermal Properties

et al. 2022

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Polylactide (PLA) stereocomplexes (SCs) containing amorphous block copolymers have gained enormous interest due to their unique properties and wide range of potential applications. In this work, we report the synthesis and properties of non-covalent triblock terpolymers: polystyrene−SCPLA−polyisoprene (PS−SC−PI) via the stereocomplexation of PS-b-PDLA with PI-b-PLLA diblock copolymers through the solutionprecipitation method. The diblock copolymers were prepared by combining the anionic polymerization high-vacuum technique with ring-opening polymerization (ROP). First, several well-defined ω-hydroxyl polystyrenes and polyisoprenes (PS-OH and PI-OH) with varied molecular weights were synthesized by anionic polymerization using sec-BuLi as the initiator. PS-OH and PI-OH were used as the macroinitiators for the ROP of DLA and LLA catalyzed by tin(II) 2-ethyl hexanoate to afford PS-b-PDLA and PI-b-PLLA. PS−SC−PIs were prepared by mixing PS-b-PDLA and PI-b-PLLA solutions (in dichloromethane) and precipitated into methanol. The molecular characteristics of the block copolymers were determined by 1 H NMR spectroscopy and size exclusion chromatography. The formation of PS−SC−PIs was evidenced by differential scanning calorimetry, X-ray diffraction, and Fouriertransform infrared, and circular dichroism spectroscopies. A preliminary study by atomic force microscopy reveals the thin-film phase behavior and the supramolecular organization of the PS−SC−PI.

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Section: ■ Results and Discussionmentioning

confidence: 99%

“…The ω-hydroxyl functionalized PS and PI were obtained by termination of the alkoxy anion with methanol. In general, the end-capping of the living chain end with EO followed by the addition of methanol results in OH-functionalized polymers with a high degree of functionalization (>99%). , …”

Section: Results and Discussionmentioning

confidence: 99%

Non-Covalent PS–SC–PI Triblock Terpolymers via Polylactide Stereocomplexation: Synthesis and Thermal Properties

et al. 2022

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“…However, difunctional initiators have low solubility especially in hydrocarbon solvents and initiation processes are slow, leading to somewhat broader MWDs of the resulting linear precursors. Therefore, in later studies protected initiators were used for the polymerization processes in combination with a large variety of different linking approaches for the cyclization reactions. − By means of a different strategy, styrene was polymerized with a vinyl functionalized lithium organic initiator. The living chains were dimerized with a dichlororosilane linker and the metathesis cyclization reaction was performed with a Grubbs catalyst.…”

Section: Synthesismentioning

confidence: 99%

Topology Matters: Conformation and Microscopic Dynamics of Ring Polymers

Kruteva,

Allgaier,

Richter

2023

Macromolecules

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Ring polymers have fascinated theorists, simulators, and experimentalists as they are the simplest polymer without ends, giving rise to important topology related properties. We present the state of the art of recent synthetic efforts and investigations into the structure and dynamics of dense nonconcatenated ring polymer systems. Analyzing the existing knowledge, we identify challenges for future research: In the realm of synthesis the creation of well-defined high molecular weight rings based on different monomers are highly desirable. In the field of ring conformations, the existence of double folded structures that are at the basis of many theoretical approaches was severely challenged and further scrutiny is needed. Similarly, the issue of the size dependent transition to mass fractal structures, or the effect of local stiffness on the conformation and dynamics are open questions. The role of ring–ring threading in the terminal dynamics of rings needs to be further elucidated. In particular, the novel proposed topological glass transition for very high molecular weight ring melts awaits experimental verification. Experimentally, ring-linear blends are very seldomly investigated: only a small number of studies on the miscibility and the conformation of rings in such blends are available. Microscopic experiments on the dynamics are nearly entirely missing. Finally, as different theoretical approaches are always backed by corresponding simulations, a crucial task would be to find out how the different approaches connect to each other and which experiments should be performed.

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“…Recently, many other fascinating, complex architectures such as miktoarm stars, H-shaped, cyclic, tadpole, 8-shaped, graft copolymers, and dendrimers were synthesized by the anionic polymerization method (or through the combination with other polymerization strategies) and efficient coupling reactions. ,− Hirao and co-workers − expanded their iterative methodology by introducing new strategies leading to the synthesis of a series of well-defined exact graft and multigraft copolymers containing polar and nonpolar blocks. A significant advantage of this methodology is that complicated multistep selective reactions, generally required for synthesizing macromolecular architectures, are avoided because the polymer blocks are introduced one by one in each reaction step …”

Section: Current Status Of Living Carbanionic Polymerizationmentioning

confidence: 99%

Quo Vadis Carbanionic Polymerization?

et al. 2022

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Living anionic polymerization will soon celebrate 70 years of existence. This living polymerization is considered the mother of all living and controlled/living polymerizations since it paved the way for their discovery. It provides methodologies for synthesizing polymers with absolute control of the essential parameters that affect polymer properties, including molecular weight, molecular weight distribution, composition and microstructure, chain-end/in-chain functionality, and architecture. This precise control of living anionic polymerization generated tremendous fundamental and industrial research activities, developing numerous important commodity and specialty polymers. In this Perspective, we present the high importance of living anionic polymerization of vinyl monomers by providing some examples of its significant achievements, presenting its current status, giving several insights into where it is going (Quo Vadis) and what the future holds for this powerful synthetic method. Furthermore, we attempt to explore its advantages and disadvantages compared to controlled/living radical polymerizations, the main competitors of living carbanionic polymerization.

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Well-defined cyclic polymer synthesis via an efficient etherification-based bimolecular ring-closure strategy

Abstract: An alternative method to synthesize well-defined cyclic polymers via combination of anionic polymerization high vacuum techniques and Williamson etherification reaction in moderate dilution and up to 1 g scale.

Cited by 7 publications

References 46 publications

Non-Covalent PS–SC–PI Triblock Terpolymers via Polylactide Stereocomplexation: Synthesis and Thermal Properties

Non-Covalent PS–SC–PI Triblock Terpolymers via Polylactide Stereocomplexation: Synthesis and Thermal Properties

Topology Matters: Conformation and Microscopic Dynamics of Ring Polymers

Quo Vadis Carbanionic Polymerization?

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