Probing the two-stage transition upon crossing the glass transition of polystyrene by solid-state NMR

Peng, Yong-jin; Cai, Chenting; Zhang, Rongchun; Chen, Tie-hong; Sun, Pingchuan; Li, Baohui; Wang, Xiaoliang; Xue, Gi; Shi, An‐Chang

doi:10.1007/s10118-016-1762-z

Cited by 8 publications

(3 citation statements)

References 75 publications

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“…Another technique to investigate the glass transition in polymers is nuclear magnetic resonance (NMR). It provides valuable information that provides deeper insight into the properties of materials at the molecular level [68][69][70][71][72][73][74]. The NMR techniques make it possible to monitor the complex dynamics behavior of glassy polymers over a wide range of time scales by measuring different relaxation times, which dramatically change when the polymers undergo glass transition.…”

Section: Tg Measurement Methodsmentioning

confidence: 99%

Review of Recent Developments of Glass Transition in PVC Nanocomposites

et al. 2021

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This review addresses the impact of different nanoadditives on the glass transition temperature (Tg) of polyvinyl chloride (PVC), which is a widely used industrial polymer. The relatively high Tg limits its temperature–dependent applications. The objective of the review is to present the state–of–the–art knowledge on the influence of nanofillers of various origins and dimensions on the Tg of the PVC. The Tg variations induced by added nanofillers can be probed mostly by such experimental techniques as thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and dielectric thermal analysis (DETA). The increase in Tg is commonly associated with the use of mineral and carbonaceous nanofillers. In this case, a rise in the concentration of nanoadditives leads to an increase in the Tg due to a restraint of the PVC macromolecular chain’s mobility. The lowering of Tg may be attributed to the well–known plasticizing effect, which is a consequence of the incorporation of oligomeric silsesquioxanes to the polymeric matrix. It has been well established that the variation in the Tg value depends also on the chemical modification of nanofillers and their incorporation into the PVC matrix. This review may be an inspiration for further investigation of nanofillers’ effect on the PVC glass transition temperature.

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Section: Tg Measurement Methodsmentioning

confidence: 99%

Review of Recent Developments of Glass Transition in PVC Nanocomposites

et al. 2021

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“…194 By using 13 C CODEX, 1 H dipolar filter, and the double-quantum filter NMR experiment, Sun et al found a two-stage transition when increasing the temperature to above T g , where the first stage involves the reorientation motion of polymer backbone chains and the second stage is related to the melting of the glassy components. 195 H labeling, where the 1 H signals of protons in close proximity will be filtered out, leaving only protons that are within a 1 H− 2 H distance of about 0.5 nm. 196 Therefore, by controlling interchain proximity, they found that enthalpy relaxation of polystyrene (PS) is actually mainly affected by the local segmental motions on short length scales.…”

Section: Discrete Motions In a Crystallinementioning

confidence: 99%

“…Using the same approach, White et al directly quantified the conformer interchange time scale of pure polyisobutylene to be around several seconds over the calorimetric T g range, as well as the changes of configuration entropy upon mixing with other polymers, in combination with Adams–Gibbs theory . By using 13 C CODEX, 1 H dipolar filter, and the double-quantum filter NMR experiment, Sun et al found a two-stage transition when increasing the temperature to above T g , where the first stage involves the reorientation motion of polymer backbone chains and the second stage is related to the melting of the glassy components . Note that different characterization techniques are sensitive to different motional time scales, and thus the correlation among experimental results from different techniques should be carefully examined.…”

Section: Molecular Dynamicsmentioning

confidence: 99%

Elucidations of Structure and Molecular Dynamics of Complex Polymers by State-of-the-Art Solid-State NMR Spectroscopy

Zhang,

Chen,

Miyoshi

2024

Macromolecules

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Solid-state nuclear magnetic resonance (ssNMR) has been playing an indispensable role in revealing the interplay of structure and molecular dynamics in polymers at different states. In this Perspective, we first provide an overview about the fundamental spin interactions in ssNMR and then highlight some recent progress on sensitivity-enhanced ssNMR spectroscopy and in situ NMR. Moreover, we highlight ssNMR applications in the field of polymer crystallization, molecular dynamics, chemical reactions, supramolecular polymers, energy materials, and so on. Finally, our personal perspective is given on the future development at the crossroad of ssNMR and polymer science.

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On the Dynamic Mechanical Behavior and Importance of Weak Interactions in PS/PVME Blends

2020

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In this work, the dynamic mechanical behavior and weak interactions in a miscible blend of polystyrene/poly (vinyl methyl ether) (PS/PVME) with a mass ratio of 3 : 1 (PS/PVME 75/25) were studied using DMA detection and solid‐state NMR methods. The results showed the miscibility of the blend and the evidence of the weak C−H to O hydrogen bonding between the aromatic H in PS and O of the methoxyl group in PVME. The 1H‐13C correlation spectrum indicated the diffusion time between 13C in OCH/OCH3 of PVME and Aromatic 1H of PS was at about millisecond level which confirmed the space affinity between the Aromatic 1H and OCH/OCH3 group in this mixture. Quantum calculations were made with four model systems in solutions by comparing the solvent toluene with CHCl3. In this way it was shown that the binding energy between PVME and CHCl3 was larger than the one between PVME and toluene, explaining why PVME and PS were miscible when using toluene as a solvent but not in CHCl3. The detailed components of the binding energy between PVME and solvent molecules were also analyzed with different methods which showed the similar result. These results reported here allows opportunities for finding new blend dependent on this kind of weak interaction or design of special polymers to enhance such weak interactions.

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Probing the two-stage transition upon crossing the glass transition of polystyrene by solid-state NMR

Cited by 8 publications

References 75 publications

Review of Recent Developments of Glass Transition in PVC Nanocomposites

Review of Recent Developments of Glass Transition in PVC Nanocomposites

Elucidations of Structure and Molecular Dynamics of Complex Polymers by State-of-the-Art Solid-State NMR Spectroscopy

On the Dynamic Mechanical Behavior and Importance of Weak Interactions in PS/PVME Blends

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