- Author
- Bourbigot, S. P. | Vanderhart, D. L. | Gilman, J. W. | Bellayer, S. | Stretz, H. | Paul, D. R.
- Title
- Solid State NMR Characterization and Flammability of Styrene-Acrylonitrile Copolymer Montmorillonite Nanocomposite.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD Texas State University, San Marcos, TX University of Texas, Austin, TX
- Journal
- Polymer, Vol. 45, No. 22, 7627-7638, October 2004
- Keywords
- copolymers | nonocomposites | solid state | flammability
- Identifiers
- solid state nuclear magnetic resonance; styrene-acrylonitrile copolymer
- Abstract
- This work investigates the melt-processing of styrene-acrylonitrile copolymer (SAN) with organo-modified montmorillonite (MMT) clays and the influence of the clay on mechanical properties and on fire performance of SAN. The nanodispersion of MMT is evaluated qualitatively by X-ray diffraction (XRD) and transmission electronic microscopy (TEM), and quantitatively by solid state nuclear magnetic resonance (NMR). SAN/MMT nanocomposites reveal an intermediate morphology, an intercalated structure with some exfoliation and with the presence of small tactoids, whatever the loading in MMT is. The polymer-clay interfacial area is estimated at 0.5 and the degree of homogeneity characterizing the distribution of MMT platelets is about 40%. The presence of clay in SAN-25 leads to a "filler effect" increasing the stiffness but decreasing tensile strength of the nanocomposites. It also leads to a significant decrease of peak of heat release rate measured by mass loss calorimetry.