Rheology and structure of immiscible polymer blends filled with carbon black

In this contribution immiscible polystyrene/polymethylmethacrylate (PS/PMMA) blends filled with carbon black (CB) are investigated in a broad composition range. In these blends carbon black is localized preferentially in polystyrene phase. The influence of carbon black on blends phase structure is evaluated and consequently rheology and electrical conductivity is discussed. Pronounced differences in the morphology of unfilled and filled blends were observed in cases, in which PS phase containing CB forms a minor phase. Dispersed morphology with spherical particles and sharp interfaces turned by addition of 3 vol.% of CB into partially co-continuous morphology with irregular domain shapes. This morphology change was detected even in blends with PS content as low as 10 vol.%. The rheology of the blends was largely influenced by the addition of CB in the systems with PS matrix.