Fabrication of Polyethylene-grafted SiO₂ Nanoparticles and their Application to Polyethylene-based Nanocomposites

Abstract

Polyethylene (PE)-based nanocomposites were developed using PE-grafted SiO₂ (PE-g-SiO₂) nanoparticles, which were prepared by grafting terminally hydroxylated PE having different molecular weights. The obtained PE/PE-g-SiO₂ nanocomposites were characterized in terms of the nanoparticle dispersion, the crystallization, and the tensile properties in a comparative way to pristine PE, PE/SiO₂ nanocomposites and previously reported polypropylene (PP)/PP-g-SiO₂ nanocomposites. Similarly to the PP grafting, the PE grafting markedly improved the dispersion of the nanoparticles in the corresponding matrix and accelerated the crystallization. The addition of 5.0wt% of PE-g-SiO₂ led to increments of the Young’s modulus and tensile strength over pristine PE by 23% and 11%, respectively, while the addition of unmodified SiO₂ hardly improved these properties. The reinforcing mechanism in the PE/PE-g-SiO₂ nanocomposites was also discussed.