Nanocomposites based on polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene and exfoliated graphite nanoplates: Effect of nanoplatelet loading on morphology and mechanical properties

Exfoliated graphite nanoplates (xGnPs)/polystyrene-b-poly(ethylene-r-butylene)-b-Polystyrene (SEBS) nanocomposites have been prepared by the simple melt-compounding approach. The structural, mechanical and viscoelastic properties of these composites were studied and compared. Wide-angle X-ray diffraction (WAXD) studies indicated that the processing of nanocomposites did not change the original d-spacing of xGnPs. Scanning electron microscopy observation on the fracture surfaces of the composites shows a uniform dispersion of xGnPs throughout SEBS matrix and strong interfacial adhesion between oxidized xGnPs and the matrix, which are responsible for the considerable enhancement of mechanical properties of the composites. It is found that the addition of xGnPs particles improved both the elastic modulus and storage modulus of pure SEBS significantly and the higher the xGnPs content, the higher the modulus of the nanocomposite. Moreover, the effects of dispersed xGnPs on the microphase separation of SEBS have also been investigated using small angle X-ray scattering (SAXS). (C) 2011 Elsevier Ltd. All rights reserved.