Imidazolium-modified clay-based ABS nanocomposites: a comparison between melt-blending and solution-sonication processes

Acrylonitrile–butadiene–styrene (ABS) nanocomposites containing imidazolium-modified montmorillonite have been prepared by melt-blending (MB) and solution-sonication in order to study the effects of processing on the morphology and properties of the polymer/clay composites. The structure-property relationships of the prepared composites have been studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), mechanical testing, dynamic-mechanical analyses (DMA), thermal gravimetrical analyses (TGA), fluorescence probe confocal microscopy, and fluorescence spectroscopy (FS). X-Ray and TEM show that both nanocomposites have a mixed intercalated/exfoliated structure. Fluorescence probe confocal microscopy reveals that the sonicated sample has a more homogeneous dispersion: this result is confirmed by the values of elongation at break and flexural elastic modulus measured for the composites. Fluorescence spectroscopy has also been used to investigate the distribution of clay in the composites and results indicate that clay layers in ABS are preferentially located in the styrene-acrylonitrile (SAN) phase, independent of the dispersion process used.