Filler Migration in Natural Rubber Blends During the Mixing Process
The development of nanofiller localization (silica, carbon black, carbon nanotubes, nanoclay) and blend morphology of rubber blends consisting of natural rubber and different synthetic rubbers during mixing process was described comprehensively by combination of our developed methods. The dispersion kinetics of several fillers along the mixing time could be well characterized by the method of online measured electrical conductance. The phase selective filler localization in binary and ternary rubber blends as function of mixing time was experimentally determined by means of the wetting concept. For a quantitative prediction of filler localization in rubber blends the so-called Z-model based on thermodynamic data was proposed. Compared to synthetic blend partners like SBR, BR or EPDM, NR exhibits a high filler wetting speed and low filler–rubber interaction that leads to a complex behaviour of filler localization in natural rubber blends. The effect of material and technological parameters on the localization kinetics of different fillers and its effect on the mechanical properties of blends are the focus of the present work.