Processing and characterization of carbon nanotube/poly(styrene-co-butyl acrylate) nanocomposites

Nanocomposite materials were prepared from an amorphous poly(styrene-co-butyl acrylate) latex as the matrix using an aqueous suspension of carbon nanotubes as the filler. After stirring, the preparations were cast and evaporated. The morphology of the resulting films was examined by scanning electron microscopy and a good dispersion of the filler was observed, except for the 5 wt% filled sample. The electrical conductivity and mechanical behavior in both the linear and non-linear ranges were analyzed. From conductivity measurements, a clear percolation threshold has been observed for a relatively low critical volume fraction around 1.5%. The mechanical characterization displayed a continuous reinforcing effect of the carbon nanotubes without lowering of the elongation at break up to 3 wt%. The thermal stability of the composites was strongly improved by carbon nanotubes loading. For instance, the terminal zone was shifted by 115 K with only 15 wt% of nanotubes. (C) 2002 Kluwer Academic Publishers.