ABS/clay nanocomposites obtained by a solution technique: Influence of clay organic modifiers

Acrylonitrile-butadiene-styrene (ABS) polymer/clay nanocomposites were produced using an intercalation\u2013adsorption technique from polymer in solution: polymer/clay suspensions were subjected to ultrasonic processing to increase the effectiveness of mixing. Several kinds of organically modified layered silicates (OMLS) were used to understand the influence of the surfactant nature on the intercalation\u2013exfoliation mechanism. We show that only imidazolium-treated montmorillonite (DMHDIM-MMT) is stable at the processing temperature of 200 \ub0C, used for hot-pressing, whereas alkyl-ammonium modified clays show significant degradation. The morphology of ABS based polymer nanocomposites prepared in this work was characterized by means of wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Dynamic-mechanical analysis (DMA) was used to determine the storage modulus and damping coefficient as a function of temperature, and to investigate the correlations between mechanical properties and morphology of the nanocomposites. The thermal stability was assessed by means of thermogravimetric analysis (TGA). DMA and TGA show that the nanocomposites based on imidazolium-modified clay out-perform the nanocomposites based on quaternary-ammonium-modified clays in terms of mechanical properties and thermal stability

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