A Comparative Study on the Properties of ABS/Clay Nanocomposites Prepared by Direct Melt Intercalation and In-situ Emulsion Polymerization Techniques.

Polybutadiene (PS) and acrylonitrile-butadiene-styrene (ASS) latexes were prepared by emulsifier-free emulsion polymerization. ASS/Montmorillonite (MMT) nanocomposites containing 5 wt% clay loadings were also synthesized by insitu emulsifier-free emulsion polymerization method using a reactive in-situ clay modifier, and by direct melt intercalation technique using two different organoclays. The morphology and thermal stability of the nanocomposites were examined using X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD and TEM results showed exfoliated-intercalated morphology with more uniform distribution of the clay layers for the nanocomposite prepared by in-situ emulsion polymerization, and intercalated morphologies with clay aggregates containing more clay layers for the nanocomposites prepared by direct melt intercalation technique. The basal spacing for the nanocomposite prepared by in-situ emulsion polymerization technique was calculated as 1.73 nm which was lower than 3.36 and 3.52 nm calculated for the melt intercalated nanocomposites using organoclays with one and two octadecyl chains in the organic modifier molecule, respectively. The TGA results showed an increase in the onset thermal degradation temperatures of the nanocomposites. The peak weight loss rate temperatures were obtained as 462.1, 470.4,497.7 and 492.2°C for neat ASS, in-situ emulsion polymerized and melt intercalated nanocomposites using organoclays with one and two octadecyl chains in the organic modifier molecule, respectively.