Effect of Carbon Nanotube Functionalization on the Structural and Mechanical Properties of Polypropylene/MWCNT Composites

Multiwall carbon nanotubes (MWCNTs) have been functionalized via addition of undecyl (C11-) radicals generated by thermal decomposition of lauroyl peroxide. The functionalized MWCNTs (C11-MWCNTs) were characterized by Raman, IR spectroscopy, and thermogravimetric analysis (TGA). Isotactic polypropylene (iPP) and syndiotactic polypropylene (sPP) nanocomposites containing both purified and alkyl-functionalized MWCNTs have been synthesized via in situ polymerization method with the use of C2- and Cs-symmetry zirconocenes activated by MAO in liquid propylene medium. The effect of incorporating C11-MWCNTs on structural, electrical, and mechanical properties of the polypropylene-based nanocomposites has been studied. Analysis of electrical properties in the microwave range elucidates interfacial transformations in the composites induced by MWCNT functionalization and evaluates relative aspect ratios for the filler particles in different systems. The synthesized materials demonstrate improved filler dispersion a...