Segmental Dynamics and Cooperativity Length of PMMA/SAN Miscible Blend Intercalated in Organically Modified Nanoclay
| Autor: | Nader Taheri-Qazvini, Ehsan Chehrazi |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Nanocomposite Materials science Cooperativity 02 engineering and technology Surfaces and Interfaces Polymer Dynamic mechanical analysis 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Molecular dynamics chemistry.chemical_compound Differential scanning calorimetry Fragility Chemical engineering chemistry Electrochemistry General Materials Science Methyl methacrylate 0210 nano-technology Spectroscopy |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 34(47) |
| ISSN: | 1520-5827 |
| Popis: | The effect of nanoconfinement on the segmental dynamics of a poly(methyl methacrylate) (PMMA)/poly(styrene-ran-acrylonitrile) (SAN) miscible blend, intercalated into the interlayer spacing of the organically modified nanoclay (OMNC), was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) methods. We reported an unusual phenomenon in which the weak interfacial interactions between the polymer chains and OMNCs was responsible for increase in segmental mobility at the glass-transition temperature (Tg). Remarkably, we found a positive correlation between dynamic fragility and thermodynamic fragility, in which both fragilities decreased under nanoconfinement. The cooperative length of segmental motions, or length of cooperatively rearranging regions, ξCRR, decreased from 2.64 nm for the PMMA/SAN blend to 1.86 nm for the PMMA/SAN/OMNC nanocomposite. The segmental mobility of the PMMA/SAN/OMNC model was also studied using the molecular dynamics simulations. The simul... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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