Functionalization of multi-wall carbon nanotubes with silane and its reinforcement on polypropylene composites

Multi-wall carbon nanotubes (MWCNTs) were functionalized with a silane coupling agent. The MWCNTs were first coated with inorganic silica by a sol–gel process and then grafted with 3-methacryloxypropyltrimethoxysilane (3-MPTS). The grafting of 3-MPTS onto the MWCNTs surface was confirmed by Fourier-transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectra. Polypropylene (PP) composites filled with raw MWCNTs and functionalized MWCNTs were prepared and characterized. The PP/3-MPTS functionalized MWCNTs composite has higher tensile strength than the PP/raw MWCNTs composite. This is explained by the organic groups of 3-MPTS grafted onto the surface of MWCNTs.