Effect of nano-SiO2 particle size on the formation of LLDPE/SiO2 nanocomposite synthesized via the in situ polymerization with metallocene catalyst

Here, we revealed the effect of particle size of the nanoscale SiO₂ on catalytic and characteristic properties of LLDPE/nano-SiO₂ composites synthesized via the in situ polymerization with a zirconocene/MAO catalyst. In the experiment, SiO₂ (10 and 15 nm) was first impregnated with MAO. Then, copolymerization of ethylene/1-hexene was performed in the presence of nano-SiO₂/MAO to produce LLDPE/nano-SiO₂ composites. It was found that the larger particle exhibited higher polymerization activity due to fewer interactions between SiO₂ and MAO. The larger particle also rendered higher insertion of 1-hexene leading to decreased melting temperature (T_m). There was no significant change in the LLDPE molecular structure by means of ¹³C NMR.