@article{3036910, title = "Structure-property relationships in isotactic polypropylene/multi-walled carbon nanotubes nanocomposites", author = "Logakis, E. and Pollatos, E. and Pandis, Ch. and Peoglos, V. and Zuburtikudis, I. and Delides, C.G. and Vatalis, A. and Gjoka, M. and Syskakis, E. and Viras, K. and Pissis, P.", journal = "Composites Science and Technology", year = "2010", volume = "70", number = "2", pages = "328-335", issn = "0266-3538", doi = "10.1016/j.compscitech.2009.10.023", keywords = "A. Carbon nanotubes; B. Thermomechanical properties; Broadband dielectric relaxation spectroscopy; Crystallinities; Crystallization behavior; Dc conductivity; Degree of crystallinity; Dielectric constant values; Electrical and dielectric properties; Electrical percolation threshold; Electrical property; Glassy state; Isotactic poly(propylene) (iPP); Isotactics; Masterbatch; matrix; Melt mixing; SEM; Storage moduli; Structure property relationships; Thermal and mechanical properties; Thermal transitions; Thermomechanical properties; XRD measurements, Carbon nanotubes; Crystallization; Differential scanning calorimetry; Dynamic analysis; Dynamic mechanical analysis; Mechanical properties; Multiwalled carbon nanotubes (MWCN); Nanocomposites; Percolation (computer storage); Percolation (fluids); Percolation (solid state); Permittivity; Polypropylenes; Reconnaissance aircraft; Reinforced plastics; Solvents; Spectroscopy; Thermomechanical treatment, Electric properties, crystallization; electrical property; mechanical property; morphology; nanocomposite; nanotube; polypropylene; structural property; thermal property", abstract = "In this work, the influence of multi-walled carbon nanotubes (MWCNT) on electrical, thermal and mechanical properties of CNT reinforced isotactic polypropylene (iPP) nanocomposites is studied. The composites were obtained by diluting a masterbatch of 20 wt.% MWCNT with a low viscous iPP, using melt mixing. The morphology of the prepared samples was examined through SEM, Raman and XRD measurements. The effect of MWCNT addition on the thermal transitions of the iPP was investigated by differential scanning calorimetry (DSC) measurements. Significant changes are reported in the crystallization behavior of the matrix on addition of carbon nanotubes: increase of the degree of crystallinity, as well as appearance of a new crystallization peak (owing to trans-crystallinity). Dynamic mechanical analysis (DMA) studies revealed an enhancement of the storage modulus, in the glassy state, up to 86%. Furthermore, broadband dielectric relaxation spectroscopy (DRS) was employed to study the electrical and dielectric properties of the nanocomposites. The electrical percolation threshold was calculated 0.6-0.7 vol.% MWCNT from both dc conductivity and dielectric constant values. This value is lower than previous mentioned ones in literature in similar systems. In conclusion, this works provides a simple and quick way for the preparation of PP/MWCNT nanocomposites with low electrical percolation threshold and significantly enhanced mechanical properties. © 2009 Elsevier Ltd. All rights reserved." }