Study on Preparation and Properties of Silane-crosslinked Polyethylene/ Magnesium Hydroxide/ Montmorillonite Nanocomposites

Silane-crosslinked polyethylene/magnesium hydroxide/organomontmorillonite nanocomposite is prepared from linear low density polyethylene (LLDPE), vinyltrimethoxysilane, magnesium hydroxide (MH), and organo-montmorillonite (OMT). The morphology is characterized by the X-ray diffraction and high resolution electron microscopy. It is indicated that the intercalated morphology is formed in the polymer matrix. The mechanical properties, thermal stability, flammability, and crystallization are investigated by tensile, limiting oxygen index, cone calorimetry, thermogravimetry, and differential scanning calorimetry experiments. Results indicate that the crosslinked nanocomposite shows lower thermal-oxidative stability and fire safety than the crosslinked LLDPE/MH composite at the same additive level, the reason is postulated to be that the presence of MH and OMT decreases the crosslinking degree and the crosslinking network structure prevents the migration of OMT layers to the surface.