Stability parameters for mineral suspensions: Improving the dispersion of fillers in thermoplastics

The study of the stability of mineral suspensions using Hansen solubility parameters (HSP) has been developed to predict and optimize the dispersion of mineral particles in thermoplastics, in order to prevent the agglomeration of particles leading to a decrease in polymer performances. In our study, this approach was applied to an innovative approach for the management of silica fume (SF) waste, consisting in using this by-product as a filler for polypropylene. The determination of the stability coefficient took into account the main dispersion parameters, which thus also provided a stability map, enabling a surface modification of the SF to be defined that makes it highly suitable for incorporation in polypropylene. We present chemical surface treatments with octadecylamine to illustrate this approach.