Influence of dispersants on the flow behaviour of unsaturated polyester–alumina composites

The influence of commercially available dispersants on the rheological behaviour of an unsaturated polyester–alumina composite was systematically investigated. In addition, the effect of a chemical surface hydrophobisation using a silanisation agent was determined. In few cases, a significant change of the flow properties could be observed, a selection of suitable dispersants, which reduce the composite's viscosity will be presented. Furthermore the influence of the alumina content, the filler's surface polarity and the dispersion method on the composite's viscosity was investigated and compared with empirical models for the estimation of the critical filler load.