Thermal degradation behaviour of PE/clay nanocomposites

Polymer nanocomposites based on organically modified clay (organoclay) and polyethylene (PE) were prepared by melt processing using poly(ethylene-co-vinyl acetate) (EVA) as compatibilizer. The degree of intercalation spacing was determined by X-ray diffraction (XRD). The thermal degradation behaviour was studied in thermogravimetry (TGA) and the chemical evolution in the solid residue was studied with an infrared microscope. During the thermal degradation of the nanocomposite in oxidant atmosphere the formation of a protective layer on the polymer surface was observed caused by a charring process of PE, which is normally a non-char-forming polymer. The protective effect of the char/clay layer against thermal oxidation was also observed by monitoring the retention of the long chain structure of PE.