Polypropylene-graft-maleic anhydride-nanocomposites: I - Characterization and thermal stability of nanocomposites produced under nitrogen and in air

The morphology and thermal behaviour of polypropylene-graft-maleic anhydride (PP-g MA) layered silicate (montmorillonite) nanocomposites were investigated using X-ray diffraction, transmission electron microscopy, differential scanning calorimetry and thermogravimetry. The study focuses on the influence of the presence of oxygen during the preparation of PP-g-MA-nano-composite using two different modified clays. The nanocomposites show tactoid, intercalated and exfoliated structures side by side with different dominant states depending on the clay used and on the processing conditions. The systems are described as multicomponent blends rather than binary blends since the organic ions do not only change the mixing behaviour, but also influence material properties. Beside the physical barrier property of the clay layers also chemical processes were found to play an important role. (C) 2003 Elsevier Ltd. All rights reserved.