Synthesis of linear polyglycerols with tailored degree of methylation by copolymerization and the effect on thermorheological behavior

Schubert, Christian; Dreier, Philip; Nguyen, T. D.; Maciol, Kamil; Blankenburg, Jan; Friedrich, Christian; Frey, Holger

doi:10.1016/j.polymer.2017.05.030

Cited by 8 publications

(10 citation statements)

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“…An explanation for such an enhancement is a severe alteration of chain conformations in the interfacial layer surrounding segregated end-group clusters and the very small distance between them. Here, the regular structure of telechelic systems with uniform chain lengths between stickers seems relevant, in contrast to randomly functionalized systems with a distribution of sticker separations and far smaller modulus enhancement . These results demonstrate the great potential of supramolecular reversible bonds combined with phase separation behavior for design of functional recyclable materials with unique properties.…”

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confidence: 78%

“…Supramolecular association is a thriving concept to develop novel functional and responsive materials. − Mimicking many examples from Nature, − hierarchical superstructures formed by transient networks give rise to highly desirable properties such as self-healing, − superstretchability, mechanical enhancement, recyclability, − and so on. , In order to fully incorporate this concept into technology and materials design, it is crucial to understand the details of the association process on the molecular scale and the relations to the resulting macroscopic properties. An analysis of linear polymers with hydrogen-bonding end groups demonstrated that the Bond Lifetime Renormalization Model (BLRM) can quantitatively describe the relation between molecular associations and macroscopic network relaxation. , This enables one to predict material performance based on its chemical structure, that is, it provides a big step toward the rational design of functional materials.…”

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confidence: 99%

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Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation

Treß

Xing

et al. 2021

ACS Macro Lett.

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Supramolecular associations provide a promising route to functional materials with properties such as self-healing, easy recyclability or extraordinary mechanical strength and toughness. The latter benefit especially from the transient character of the formed network, which enables dissipation of energy as well as regeneration of the internal structures. However, recent investigations revealed intrinsic limitations in the achievable mechanical enhancement. This manuscript presents studies of a set of telechelic polymers with hydrogen-bonding chain ends exhibiting an extraordinarily high, almost glass-like, rubbery plateau. This is ascribed to the segregation of the associative ends into clusters and formation of an interfacial layer surrounding these clusters. An approach adopted from the field of polymer nanocomposites provides a quantitative description of the data and reveals the strongly altered mechanical properties of the polymer in the interfacial layer. These results demonstrate how employing phase separating dynamic bonds can lead to the creation of high-performance materials.

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mentioning

confidence: 78%

mentioning

confidence: 99%

Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation

Treß

Xing

et al. 2021

ACS Macro Lett.

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“…to PG chains, which enriches the therapeutic profile of the micellar carrier and expands the variety of possible biomedical and pharmaceutical applications . Generally, linear PG can be obtained via ring-opening anionic polymerization of glycidyl ethers (protected glycidols) and subsequent cleavage of the protective groups. − The preparation of PG-based linear amphiphilic AB, ABA, and ABC block co(ter)polymers and other architectures usually involves polymerization of protected glycidol from a macroinitiator. Thus, polystyrene- b -polyglycidol diblock copolymers have been synthesized by Siebert et al via sequential anionic polymerization of styrene initiated with sec -butyl lithium followed by polymerization of EEGE in the presence of a phosphazene base and deprotection of PEEGE blocks by acidic hydrolisis .…”

Section: Introductionmentioning

confidence: 99%

Linear Amphiphilic Polyglycidol/Poly(ε-caprolactone) Block Copolymers Prepared via “Click” Chemistry-Based Concept

et al. 2019

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We introduce a "click" chemistry-based concept for the preparation of amphiphilic block copolymers comprising linear polyglycidol (PG). Herein, a new class of linear polyglycidol/poly(ε-caprolactone) (PG/PCL) block copolymers of precisely designed macromolecular characteristics and composition was synthesized to demonstrate the convenience of this strategy. Monohydroxyl poly(ethoxyethylglycidyl ether) (PEEGE) precursors were synthesized by ring-opening anionic polymerization of ethoxyethylglycidyl ether (EEGE) and subsequently functionalized with a "clickable" alkyne end group. In parallel, a bifunctional PCL diol was modified to an azide-terminated macroreagent. PG/PCL block copolymers were obtained by "click" coupling reaction of the alkyn-and azide-functional macroreagents in the presence of a CuBr/PMDETA catalytic complex and subsequent cleavage of the protective ethoxyethyl groups of PEEGE. The amphiphilic block copolymers were not directly soluble in water, and defined nano-sized micelles were obtained via the solvent evaporation method. The synthesis pathway described here can be extended toward synthesis of various functional block copolymers comprising linear PG.Recent advances in polymer chemistry have enabled the synthesis of amphiphilic macromolecules with controlled length, topology, and well-defined positions of functional groups along the chain. This offers many possibilities for fabricating desired nanoscale structures with tailored properties by design of novel copolymer molecules. For example, the pioneering works devoted to micellar carriers for nanomedicine have been focused mainly on the formation of core−shell micelles, loading with active substances, and in vitro release studies, while nowadays, more complex functional systems combining a variety of properties and allowing for the simultaneous performance of multiple functions in in vivo conditions are being investigated. 4 It is not unexpected that the spectrum of micellar characteristics such as size, loading capacity, elimination time, cell penetration ability, and drug release profile has been remarkably improved or optimized.

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“…The synthesis of P(GME- co -EGE) was investigated under AROP as well as MAROP conditions, illustrating the impact of polymerization technique on the microstructure. The implementation of the Fineman–Ross model revealed a slight gradient microstructure when employing AROP ( r GME = 1.31, r EGE = 0.55), whereas MAROP afforded random copolymers ( r GME ≈ r EGE ), as determined by applying the Kelen-Tüdös evaluation method. , The MAROP of GME with ethoxy ethyl glycidyl ether (EEGE) evaluated using the nonterminal Jaacks model equally showed a random-type copolymerization behavior . Noteworthy, these are the only results evaluated by in situ 1 H NMR kinetics, enabling a precise understanding of the monomer sequence statistics along the polyether chains.…”

Section: Copolymerization Kinetics Of Scages With Other Epoxidesmentioning

confidence: 94%

“…SCAGEs enable introduction of thermoresponsive behavior in two ways: (i) by lowering the polarity of highly hydrophilic polymers, i.e., PEG and P( lin G), or (ii) by increasing the polarity of water-insoluble polymers like PPO. In this regard, the thermorheological behavior of linear polyglycerol with a tailored degree of methylation in P( lin G- co -GME) copolymers achieved by postmodification was investigated by our group in 2017 . It is worth mentioning that the incorporation of 69% GME units was necessary to enable a T cp below 100 °C (91 °C), due to the high hydrophilicity induced by H-bond formation of linear glycerol units.…”

Section: Thermosponsive Behavior Of P(scage)smentioning

confidence: 99%

Polyethers Based on Short-Chain Alkyl Glycidyl Ethers: Thermoresponsive and Highly Biocompatible Materials

Matthes

Frey

2022

Biomacromolecules

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The polymerization of short-chain alkyl glycidyl ethers (SCAGEs) enables the synthesis of biocompatible polyethers with finely tunable hydrophilicity. Aliphatic polyethers, most prominently poly(ethylene glycol) (PEG), are utilized in manifold biomedical applications due to their excellent biocompatibility and aqueous solubility. By incorporation of short hydrophobic side-chains at linear polyglycerol, control of aqueous solubility and the respective lower critical solution temperature (LCST) in aqueous solution is feasible. Concurrently, the chemically inert character in analogy to PEG is maintained, as no further functional groups are introduced at the polyether structure. Adjustment of the hydrophilicity and the thermoresponsive behavior of the resulting poly(glycidyl ether)s in a broad temperature range is achieved either by the combination of the different SCAGEs or with PEG as a hydrophilic block. Homopolymers of methyl and ethyl glycidyl ether (PGME, PEGE) are soluble in aqueous solution at room temperature. In contrast, n-propyl glycidyl ether and iso-propyl glycidyl ether lead to hydrophobic polyethers. The use of a variety of ring-opening polymerization techniques allows for controlled polymerization, while simultaneously determining the resulting microstructures. Atactic as well as isotactic polymers are accessible by utilization of the respective racemic or enantiomerically pure monomers. Polymer architectures varying from statistical copolymers, di- and triblock structures to star-shaped architectures, in combination with PEG, have been applied in various thermoresponsive hydrogel formulations or polymeric surface coatings for cell sheet engineering. Materials responding to stimuli are of increasing importance for “smart” biomedical systems, making thermoresponsive polyethers with short-alkyl ether side chains promising candidates for future biomaterials.

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Synthesis of linear polyglycerols with tailored degree of methylation by copolymerization and the effect on thermorheological behavior

Cited by 8 publications

References 53 publications

Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation

Turning Rubber into a Glass: Mechanical Reinforcement by Microphase Separation

Linear Amphiphilic Polyglycidol/Poly(ε-caprolactone) Block Copolymers Prepared via “Click” Chemistry-Based Concept

Polyethers Based on Short-Chain Alkyl Glycidyl Ethers: Thermoresponsive and Highly Biocompatible Materials

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