Polyolefin nanocomposites formed by melt compounding and transition metal catalyzed ethene homo- and copolymerization in the presence of layered silicates

摘要

Nanocomposites of high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and highly branched polyethylene rubbers were prepared both by means of melt compounding and ethene homo- and copolymerization in the presence of layered silicates which were rendered organophilic via ion exchange with various quaternary alkyl ammonium cations. In comparison to melt compounding, in-situ ethene homo- and copolymerization, catalyzed with MAO-activated zirconocene (MBI), nickel (DMN) and palladium (DMPN) catalysts, proved more effective in nanocomposite formation, as evidenced by larger interlayer spacings and formation of exfoliated anisotropic nanosilicates with high aspect ratio.