Hostname: page-component-745bb68f8f-grxwn Total loading time: 0 Render date: 2025-01-29T20:12:40.490Z Has data issue: false hasContentIssue false
  • English
  • Français

Improved Thermal Stability of Organically Modified Layered Silicates

Published online by Cambridge University Press:  01 January 2024

Rick D. Davis ,
Jeffrey W. Gilman ,
Thomas E. Sutto ,
John H. Callahan ,
Paul C. Trulove  and
Hugh C. De Long
Rick D. Davis*
Affiliation:
National Institute of Standards and Technology, Building and Fire Research Laboratories, Gaithersburg, Maryland 20899-8665, USA
Jeffrey W. Gilman
Affiliation:
National Institute of Standards and Technology, Building and Fire Research Laboratories, Gaithersburg, Maryland 20899-8665, USA
Thomas E. Sutto
Affiliation:
Naval Academy and Naval Research Laboratory, Code 6170, Washington, DC 20375, USA
John H. Callahan
Affiliation:
FDA/CFSAN, HFS 717 Instrumentation and Biophysics Branch, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA
Paul C. Trulove
Affiliation:
Air Force Office of Scientific Research, 801 Randolph St. Room 732, Arlington, Virginia 22203-1977, USA
Hugh C. De Long
Affiliation:
Air Force Office of Scientific Research, 801 Randolph St. Room 732, Arlington, Virginia 22203-1977, USA
*
*E-mail address of corresponding author: rick.davis@nist.gov
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Bromide-containing impurities were found to decrease the thermal stability of quaternary alkyl ammonium-modified layered silicates. Improved purification procedures completely removed bromide and led to a 20°C to >100°C increase in organic modified layered silicate thermal stability. Using mass spectrometry and thermal and electrochemical analysis, N,N-dimethyl-N,N-dioctadecyl quaternary ammonium-modified montmorillonite and fluorinated synthetic mica were found to degrade primarily through elimination and nucleophilic attack by these anions. The nature of residual bromides was identified and quantified, and the efficiency of removing these anions was found to be solvent dependent; sequential extraction, first ethanol then tetrahydrofuran, gave the best results. This exhaustive extraction method represents a viable alternative to the use of expensive, more thermally stable oniumion treatments for layered silicates.

Keywords

Alkyl AmmoniumMontmorilloniteNanocompositesOrganic Modifier DegradationOrganoclaySynthetic Mica
Type
Research Article
Information
Clays and Clay Minerals , Volume 52 , Issue 2 , April 2004 , pp. 171 - 179
Copyright
Copyright © 2004, The Clay Minerals Society

References

Davis, C.H. and Mathias, L.J., (2001) Self reinforcing polymeric materials. School of Polymers and High Performance Materials USA University of Southern Mississippi dissertation.Google Scholar
Davis, C.H. Mathias, L.J. Gilman, J.W. Schiraldi, D.A. Shields, R. Trulove, P. Sutto, T. and DeLong, H., (2002) Effects of melt processing conditions on the quality of poly(ethylene terephthalate) montmorillonite clay nanocomposites Journal of Polymer Science: Part B: Polymer Physics 40 2661–2666 10.1002/polb.10331.CrossRefGoogle Scholar
Davis, R.D. Gilman, J.W. and VanderHart, D.L., (2003) Processing Degradation of Polyamide-6 Montmorillonite and Clay Organic Modifier Polymer Degradation and Stability 79 111–121 10.1016/S0141-3910(02)00263-X.CrossRefGoogle Scholar
Gilman, J.W. Awad, W.H. Davis, R.D. Shields, J.R. Kashiwagi, T. VanderHart, D.L. Harris, R.H. Davis, C.H. Morgan, A.B. Sutto, T. Callahan, J. Trulove, P. and Delong, H., (2001) Polymer layered silicate nanocomposites from thermally stable trialkyl-imidazolium treated montmorillonite Chemistry of Materials 14 3776–3785 10.1021/cm011532x.CrossRefGoogle Scholar
Morgan, A.B. and Harris, J.D., (2003) Effects of organoclay soxhlet extraction on mechanical properties, flammability properties and organoclay dispersion of polypropylene nanocomposites Polymer 44 2313–2320 10.1016/S0032-3861(03)00095-8.CrossRefGoogle Scholar
Ngo, H.L. LeCompte, K. Hargens, L. and McEwn, A.B., (2000) Thermal stability of imidazolium ionic liquids Thermochimica Acta 357 97–102 10.1016/S0040-6031(00)00373-7.CrossRefGoogle Scholar
Triantafillidis, C.S. LeBaron, P.C. and Pinnavaia, T.J., (2002) Homostructured mixed inorganic-organic ion clays: A new approach to epoxy polymer-exfoliated clay nanocomposites with a reduced organic modifier content Chemistry of Materials 14 4088–4095 10.1021/cm0202862.CrossRefGoogle Scholar
Vaia, R.A. Teukolsky, R.K. and Giannelis, E.P., (1994) Interlayer structure and molecular environment of alkylammonium layered silicates Chemistry of Materials 6 1017–1022 10.1021/cm00043a025.CrossRefGoogle Scholar
VanderHart, D.L. Asano, A. and Gilman, J.W., (2001) Solid state NMR investigation of paramagnetic nylon-6 clay nanocomposites Macromolecules 34 3819–3822 10.1021/ma002089z.CrossRefGoogle Scholar
Xie, W. Gao, Z. Pan, W. Vaia, R. Hunter, D. and Singh, A., (2001) Thermal degradation chemistry of alkyl quaternary ammonium montmorillonite Chemistry of Materials 13 2979–2990 10.1021/cm010305s.CrossRefGoogle Scholar
Xie, W. Gao, Z. Liu, K. Pan, W. Vaia, R. Hunter, D. and Singh, A., (2001) Thermal characterization of organically modified montmorillonite Thermochimica Acta 367 339–350 10.1016/S0040-6031(00)00690-0.CrossRefGoogle Scholar