Campus Units

Materials Science and Engineering, Electrical and Computer Engineering, Center for Nondestructive Evaluation

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-15-2015

Journal or Book Title

Journal of Non-Crystalline Solids

Volume

410

First Page

43

Last Page

50

DOI

10.1016/j.jnoncrysol.2014.11.030

Abstract

The effect of varying amounts of montmorillonite (MMT) filler (in weight ratios of 100/0, 100/5, and 100/10) on the molecular dynamics and polarization of atactic poly(methyl methacrylate) (PMMA) is investigated using broad-band dielectric spectroscopy from 10−2 to 106 Hz and at temperatures from 30 to 140 °C. The experimental data were analyzed with the sum of Havriliak–Negami (HN) functions and a power-law conduction term. The characteristic frequency, activation energies, and dielectric strength of PMMA/MMT nanocomposites were analyzed. As MMT content increases, a Maxwell–Wagner–Sillars (MWS) relaxation emerges in the nanocomposites and the α-relaxation contributed by main-chain movements above Tg occurs at lower temperatures as silicate layers in MMT segregate PMMA chains into smaller domains. The characteristic frequency of β-relaxations is influenced by the mergence with the α-relaxation above Tg. Further, the strength of the β-relaxation is stable as a function of temperature in both pure PMMA and the PMMA/MMT nanocomposites whereas, in the nanocomposites, the strengths of the α- and MWS relaxations increase significantly with temperature up to approximately 120 °C.

Comments

This is a manuscript of an article published as Sun, Weixing, Li Li, Eduard A. Stefanescu, Michael R. Kessler, and Nicola Bowler. "Dynamics of poly (methyl methacrylate)–montmorillonite nanocomposites: A dielectric study." Journal of Non-Crystalline Solids 410 (2015): 43-50, doi:10.1016/j.jnoncrysol.2014.11.030. Posted with permission.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Copyright Owner

Elsevier B.V.

Language

en

File Format

application/pdf

Published Version

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