Mechanical properties, crystallinity, and self-nucleation of carbon nanotube-polyurethane nanocomposites

Abstract

Abstract Polyurethane nanocomposites were synthesized with different contents of oxidized multi-walled carbon nanotubes (MWCNTs). Physical and mechanical properties of the nanocomposites, such as crystallinity, dispersion of MWCNTs in the matrix, phase separation, modulus, and tensile strength were studied using differential scanning calorimetry, wide-angle X-ray diffraction, scanning electron microscopy, attenuated total reflection Fourier-transform infrared spectroscopy, and stress-strain analyses. The results showed that modulus and tensile strength were increased by incorporation of MWCNTs. In addition, phase separation of the hard and soft segments of the polyurethane matrix was increased by the addition of MWCNTs. The crystallization half-life was increased from 105 to 195 s; however, the Avrami index was reduced from 3.061 to 2.384 by the addition of MWCNTs. The width of crystals was affected by self-nucleation, where the nucleation density was varied by the addition of MWCNTs.