Morphological and electric properties of block copolymer/carbon nanotubes nanocomposites obtained by different methods

Abstract

Carbon nanotubes (CNT) nanocomposites have been widely studied in the last decades due to the interesting and significant changes that they can cause into the host polymer. These nanocomposites can be used in a very broad range of applications, for example, in the electronic or electrotechnical fields. In this study, polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene block copolymer (SEBS) and carbon nanotubes nanocomposites were prepared by two different melt blending processes. Their morphology and electrical properties were characterized. The morphology was observed and investigated by scanning electron microscopy (SEM) and rheological measurements. A good dispersion was shown by SEM analysis in spite of the presence of agglomerates. Rheological measurements also indicated a good dispersion. Upon addition of CNT, there was an increase of storage modulus (G') over the whole frequency range. Samples produced by extrusion presented a higher electrical conductivity and a lower electrical percolation threshold. Mixer process was more effective to disperse CNT in SEBS as indicated by morphological characterization.