Preparation and Characterisation of Polyethylene/Clay Nanocomposites as a Flame Retardant Materials Using Ultrasonic Technique

Three polyethylene/clay formulations (3%, 7% and 10%) were prepared by ultrasonic technique of polyethylene (PE) and montmorillonite organically modified with imidazolium salt (OMC) in toluene as solvent. The prepared PE/OMC nanocomposites were characterised by colour measurement and atomic force microscopy (AFM). An intercalated, mixed intercalated–exfoliated and delaminated structure in PE/OMC nanocomposites with different OMC content were found. The thermal stability and flammability of PE/clay nanocomposites were measured by thermogravimetric analysis (TGA) and cone calorimetry. By adding 3, 7 and 10 phr organoclay, the peak heat release rate of the nanocomposite was reduced by 34.5, 45.4 and 50.5% respectively. Further studies indicated that the improvement of flammability performance was due to the formation of a clay enriched protective char during combustion.