Synthesis of a linear low-density polyethylene/MgO@Mg(OH)₂ nanocomposite using modified in situ polymerization

Composites of linear low-density polyethylene were obtained in toluene slurry by in situ copolymerization of ethylene and 1-octene in the presence of untreated magnesium oxide–hydroxide nanoparticles (MgO@Mg(OH)₂) of ±50 nm and such treated with dibutylmagnesium (DBM) as support for a bis(n-butylcyclopentadienyl)zirconium dichloride–methylaluminoxane (MAO) catalyst system. Treatment of the nanoparticles with DBM (0.5–6 mmol g⁻¹ MgO@Mg(OH)₂) allows one to decrease the amount of MAO by 1.2 mmol Al g⁻¹ MgO@Mg(OH)₂, while reaching the same average catalyst activity and a finer distribution of the particles. Energy-dispersive X-ray mapping shows that the MAO is mainly associated with the filler. The crystallinity of the matrix polymer decreases with filler content.