Structural characterisation and thermal properties of exfoliated polystyrene/ZnAl layered double hydroxide nanocomposites prepared via solution intercalation

Exfoliated polystyrene/ZnAl layered double hydroxide (PS/ZnAl LDH) nanocomposites were synthesised by a solution intercalation method and characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). It has been found that the exfoliated LDH layers with a thickness of less than 1 nm disorderedly disperse in the PS matrix. The XRD and TEM results show that the exfoliation of LDH can be divided into solvent swelling and layer breaking processes and is affected by several reaction parameters. Completely exfoliated LDH layers can be achieved by decreasing the content of LDH, elongating the refluxing time, and rapid precipitation. The TGA data show that the PS/ZnAl LDH nanocomposites have significantly enhanced thermal stability. When 50% weight loss was selected as a point of comparison, the thermal decomposition temperature of exfoliated PS/ZnAl LDH nanocomposites with 10 wt% ZnAl LDH is 39 degreesC higher than that of pure PS. The thermal stability of the exfoliated nanocomposites is usually better than that of intercalated composites. (C) 2004 Elsevier Ltd. All rights reserved.