Sequence-Controlled α-Methylstyrene/Styrene Copolymers: Syntheses and Sequence Distribution Resolution

Wolf, Arnaud; Desport, Jessica S.; Dieden, Reiner; Frache, Gilles; Weydert, Marc; Poorters, Laurent; Schmidt, Daniel F.; Verge, Pierre

doi:10.1021/acs.macromol.0c01649

Cited by 8 publications

(10 citation statements)

References 27 publications

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“…Common one-dimensional (1D) NMR techniques (e.g., 1 H and 13 C) are often used to provide information on reaction conversion, functionalization, product purity, and monomer content. 1D NMR is particularly useful in elucidating the composition of copolymers, where recent advances of quantitative NMR measurements coupled to high-resolution mass spectrometry have enabled sequence-level characterization …”

Section: Polymer Strandsmentioning

confidence: 99%

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Molecular Characterization of Polymer Networks

et al. 2021

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Polymer networks are complex systems consisting of molecular components. Whereas the properties of the individual components are typically well understood by most chemists, translating that chemical insight into polymer networks themselves is limited by the statistical and poorly defined nature of network structures. As a result, it is challenging, if not currently impossible, to extrapolate from the molecular behavior of components to the full range of performance and properties of the entire polymer network. Polymer networks therefore present an unrealized, important, and interdisciplinary opportunity to exert molecular-level, chemical control on material macroscopic properties. A barrier to sophisticated molecular approaches to polymer networks is that the techniques for characterizing the molecular structure of networks are often unfamiliar to many scientists. Here, we present a critical overview of the current characterization techniques available to understand the relation between the molecular properties and the resulting performance and behavior of polymer networks, in the absence of added fillers. We highlight the methods available to characterize the chemistry and molecular-level properties of individual polymer strands and junctions, the gelation process by which strands form networks, the structure of the resulting network, and the dynamics and mechanics of the final material. The purpose is not to serve as a detailed manual for conducting these measurements but rather to unify the underlying principles, point out remaining challenges, and provide a concise overview by which chemists can plan characterization strategies that suit their research objectives. Because polymer networks cannot often be sufficiently characterized with a single method, strategic combinations of multiple techniques are typically required for their molecular characterization.

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Section: Polymer Strandsmentioning

confidence: 99%

“…1D NMR is particularly useful in elucidating the composition of copolymers, where recent advances of quantitative NMR measurements coupled to high-resolution mass spectrometry have enabled sequence-level characterization. 2 2.1.2. Infrared/Raman Spectroscopy.…”

Section: Polymer Strandsmentioning

confidence: 99%

Molecular Characterization of Polymer Networks

et al. 2021

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“…Poly(αMSt- co -St) resin with a molecular weight of 1820 g/mol was prepared via anionic copolymerization using the equimolar aliquot addition method, following a procedure reported previously [ 26 ]. Molecular characteristics are described in the Supplementary Materials (Section S1) .…”

Section: Methodsmentioning

confidence: 99%

“…The initial aim of this work was to fill this gap by assessing the viscoelastic properties of SBR and poly(αMSt- co -St) blends at different resin concentrations, from 25 to 150 parts per hundred rubber (phr). As the thermodynamic properties of polymer blends is highly dependent on the molecular weight [ 4 , 23 , 24 , 25 ], tailor-made and well-defined poly(αMSt- co -St) resins were prepared to avoid any side-effects from the molecular dispersity of the resin [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

An Investigation on the Thermally Induced Compatibilization of SBR and α-Methylstyrene/Styrene Resin

et al. 2021

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The miscibility between two polymers such as rubbers and performance resins is crucial to achieve given targeted properties in terms of tire performances. To this aim, α-methylstyrene/styrene resin (poly(αMSt-co-St)) are used to modify the viscoelastic behavior of rubbers and to fulfill the requirements of the final applications. The initial aim of this work was to understand the influence of poly(αMSt-co-St) resins blended at different concentrations in a commercial styrene-butadiene rubber (SBR). Interestingly, while studying the viscoelastic properties of SBR blends with poly(αMSt-co-St), crosslinking of the rubber was observed under conditions where it was not expected to happen. Surprisingly, after the crosslinking reactions, the poly(αMSt-co-St) resin was irreversibly miscible with SBR at concentrations far above its immiscibility threshold. A detailed investigation involving characterization technics including solid state nuclear magnetic resonance led to the conclusion that poly(αMSt-co-St) is depolymerizing under heating and can graft onto the chains of SBR. It results in an irreversible compatibilization mechanism between the rubber and the resin.

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“…Exploring the link between elemental kinetics and such properties is of great significance for the industrial-scale research and design. There are some publications on the micro-properties of copolymers. − Different reactors may be used for the production of a specific use of EVA; hence, micro-properties of EVA may vary with operating conditions.…”

Section: Introductionmentioning

confidence: 99%

DFT Investigation of Polyethylene-co-vinyl Acetate: Kinetics of Initiation and Propagation, Copolymer Composition, and Unit Sequence Distribution

Zhang

Chi

2022

Ind. Eng. Chem. Res.

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We conducted a kinetic investigation of initiation and propagation of copolymerization between ethylene and vinyl acetate (VAc) based on the density functional theory. Two initiators azodiisobutyronitrile and dibenzoyl peroxide were compared, and the former tends to initiate ethylene, while the latter tends to initiate β C of VAc. A calibration was performed to validate the calculation. For monomers, the reactivity follows the order α C of VAc < β C of VAc ≈ C of ethylene, while for radicals, the order is tail radical < alkyl radical < head radical. Reactivity ratios were discussed, indicating that the copolymerization is close to ideal copolymerization, especially around 430 K, and temperature is unfavorable for VAc content in the product. The relationship between monomer composition, copolymer composition, conversion, and temperature is discussed based on the kinetics calculated. Additionally, the unit sequence distribution was predicted, and the number of repetitive ethylene units can be 8–10, while VAc units often appear as 1–2. Our work gives highly reliable and comprehensive evaluation of propagation kinetics for secondary radicals in EVA copolymerization and explores the inherences of kinetic results by energy decomposition analysis. Compared with the literature, our calculation employed conformation search to average conformational deviations and considered pressure dependence, and all self- and cross-propagation modes for secondary radicals have been considered for the first time. Besides, reactivity inherences were illustrated from orbital, dispersion, repulsion, electrostatic, and entropic interactions.

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Sequence-Controlled α-Methylstyrene/Styrene Copolymers: Syntheses and Sequence Distribution Resolution

Cited by 8 publications

References 27 publications

Molecular Characterization of Polymer Networks

Molecular Characterization of Polymer Networks

An Investigation on the Thermally Induced Compatibilization of SBR and α-Methylstyrene/Styrene Resin

DFT Investigation of Polyethylene-co-vinyl Acetate: Kinetics of Initiation and Propagation, Copolymer Composition, and Unit Sequence Distribution

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