Multiwalled carbon nanotubes-reinforced isotactic polypropylene nanocomposites: Enhancement of crystallization and mechanical, thermal, and electrical properties

Multiwalled carbon nanotubes (MWCNTs)-reinforced isotactic polypropylene (iPP) nanocomposites with low-content of MWCNTs were fabricated using the melt-cast techniques. The reinforced plastics were characterized by X-ray diffraction (XRD) measurements, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, mechanical test, differential thermal analyses (DTA), and electrical tests. XRD studies exhibit the a-crystal in the injection-molded neat iPP with lamellar stacks having a long period of 150 angstrom. Both the intensity of lamellar reflection and the thickness of long period increase with increasing the MWCNTs contents, indicating an enhancement of iPP crystallization by MWCNTs addition. This increase of lamellar thickness is analyzed to be consistent with that evaluated by DTA. SEM micrographs display larger MWCNTs aggregates with increasing amount of reinforcements and show a good adhesion between nanoparticles and iPP matrix. FTIR spectra reveal distinct chemical textures for the samples and confirm the existence of a-crystal. Mechanical strengths, electrical conductivity, and dielectric constants are found to increase with increasing MWCNTs content, representing an improved performance of the nanocomposites. POLYM. COMPOS., 2012.(C) 2012 Society of Plastics Engineers