Orientation studies of uniaxial drawn syndiotactic polystyrene/carbon nanotube nanocomposite films

The response of organic-inorganic nanocomposites under deformation is important for fundamental science and practical applications. Here the orientation evolution of syndiotactic polystyrene (sPS) molecules and carbon nanotubes (CNTs) in uniaxially drawn sPS/CNT nanocomposite films were assessed by means of polarized Raman spectroscopy and infrared dichroism. The results demonstrate the preferred parallel orientation of the CNTs is along the uniaxial stretching direction in the stretched films. In addition, the presence of the CNTs has a hindrance effect on the preferred parallel orientation for the main chain (-CH2-segments) and the side groups (benzene rings) of the sPS macromolecules. The reason was attributed to the large sPS/CNT interface areas and the strong interactions (especially the pi-pi interactions between the benzene rings of sPS and the pi electrons of the CNT sidewalls). Moreover, with the increase in the draw ratio, the degree of the sPS preferred orientation in the sPS/CNT nanocomposite films increases more slowly than that in pure sPS films.