Study of LLDPE/alumina nanocomposites synthesized by insitu polymerization with zirconocene/d-MMAO catalyst

The LLDPE/Al2O3 nanocomposites synthesized by the insitu polymerization with dried-modified methylaluminoxane (d-MMAO)/zirconocene catalyst were investigated. First, after vacuum heated the Al2O3 nanofiller, the d-MMAO as the cocatalyst was impregnated onto it. Then, ethylene/1-hexene copolymerization was carried out with the presence of different amounts of d-MMAO/Al2O3 in a 100 mL semi-batch stainless steel autoclave reactor. After filtration, the obtained LLDPE nanocomposite was characterized by means of scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR). It was found that the polymerization activity strongly depended on the [Al]dMMAO/[Zr]cat ratios. The addition of Al2O3 nanofiller apparently resulted in increased melting temperature and molecular weight of LLDPE without any change in molecular weight distribution (MWD).