A facile and efficient strategy for the functionalization of multiple-walled carbon nanotubes using well-defined polypropylene-grafted polystyrene

An alternative and efficient strategy for the synthesis of polymer-modified multiple-walled carbon nanotubes (MWCNTs) using ''grafting to'' technique was demonstrated successfully. For this purpose, maleic anhydride was grafted onto polypropylene (PP) followed by opening of anhydride ring with ethanolamine to produce hydroxylated polypropylene (PP-OH). The hydroxyl groups were esterified using alpha-phenyl chloroacetyl chloride to obtain PP-Cl macroinitiator. Afterward, styrene (St) monomer was grafted onto PP through atom transfer radical polymerization technique to afford PP-g-PSt graft copolymer. The chloride-end-caped PP-g-PSt copolymer was then attached to the oxidized MWCNTs in the presence of CuBr as the catalyst to produce MWCNTs-g-(PP-g-PSt) nanocomposite. The chemical structures of all samples as representatives were characterized by means of Fourier transform infrared spectroscopy. The chemical attaching of PP-g-PSt to the MWCNTs was approved by thermal property study using thermogravimetric analysis and differential scanning calorimetry, as well as morphology studies using transmission electron and scanning electron microscopies. The synthesized MWCNTs-g-(PP-g-PSt) nanocomposite can be applied as a reinforcement for polymeric (nano-)composites due to superior features of MWCNTs as well as their compatibility with polymeric materials after functionalization processes.