Layered polymer-kaolinite nanocomposites

Kaolinite (K) was reacted with liquid dimethyl sulfoxide (DMSO) producing K(DMSO)(0.4). Highly ordered polymer/kaolinite materials were obtained by displacement of DMSO molecules in the K(DMSO)(0.4) intercalate by polyethylene oxide (PEO) or bacterial polyhydroxybutyrate (PHB), both in the melt state at 130 degrees C and 180 degrees C, respectively. The hybrid nanocomposites obtained were characterized by powder X-ray diffractometry (PXRD), Fourier Transform Infrared spectrometry (FTIR) and thermal analysis (simultaneous TG/DSC). The obtained results are consistent with the total replacement of DMSO molecules by the macromolecular linear chains that lie flat building a monolayer of the polymer in the interlayer space of kaolinite. The stoichiometry of the compounds estimated from the TG/DSC measurements are: K(DMSO)(0.40 +/- 0.02), K(PHB)(0.82 +/- 0.02), K(PEO)(3.40 +/- 0.02). (C) 2000 Kluwer Academic Publishers.