Reactor Blend and Nanocomposite of Polyethylene Using a Binary Catalyst of Metallocene/Nickel

Abstract

The present study aimed to conduct the ethylene polymerization using two binary catalytic systems to evaluate the resulting reactor blend of polyethylene. Subsequently, the study continued to explore the effects of catalyst to monomer molar ratio, reaction temperature, ethylene pressure and nanofillers on the catalysts activity, molar mass, thermal behavior, structural and morphological properties of the obtained polyethylene. The catalytic system containing α-diimine catalyst based on nickel showed higher activity, higher melting point (75.6 × 104 g polyethylene/(mol catalyst h), 125°C, respectively) and the extent of crystallinity (up to 48.5%) in comparison with the analogous system bearing pyridine-imine catalyst. The augmentation of nanoparticles increased the branching content in the system with α-diimine catalyst based on nickel, while these trends were reverse in pyridine-imine catalyst system, so that the branches were reduced as the nanoparticle concentration was increased. SEM images revealed distinct fibrous phases and the presence of obvious and well dispersed nanoparticles in the prepared nanocomposites. The synthesized polyethylene blend exhibited high thermal stability.