Mechanical, thermal and flammability properties of polyethylene/clay nanocomposites

Polyethylene/clay composites were prepared by melt compounding polyethylene and montmorillonite clay organically modified with different intercalating agents. Wide-angle X-ray diffraction (WARD) and transmission electron microscopy (TEM) revealed that PE/clay nanocomposites formed when using a reactive intercalating agent, while only conventional microcomposites were obtained from the common alkylammonium intercalated clay. Mechanical testing indicated that the reinforcement in the nanocomposites was more effective than that in their conventional counterparts. The thermal stability and flammability of the PE/clay nanocomposites were measured by thermogravimetric analysis (TGA) and cone calorimetry. By, adding only 2 phr organoclay. the peak heat release rate of the nanocomposite was reduced by 54%. Further studies indicated that the improvement of flammability is due to the formation of a clay-enriched protective char during combustion. (C) 2004 Elsevier Ltd. All rights reserved.