Structure and properties of fibrillar silicate/SBR composites by direct blend process

Silicate attapulgite(AT)/Styrene Butadiene rubber (SBR) composites with excellent properties and low cost were first prepared from a direct blending process (including polymer melt blending and emulsion co-coagulation). The structure and properties of above composites were carefully investigated. It was found that most AT separated into dispersed units with diameters less than 100 nm in SBR by the direct blend process. However, a few dispersion units as large as 0.2–0.5 μm and a clear network structure of dispersion units in SBR was observed by TEM, SEM and RPA. AT can be purified, but purified AT cannot be easily dispersed in the rubber matrix by polymer melt blending. Siliane coupling agent Si69 can improve the dispersion of AT and enhance the chemical interfacial adhesion. At the same loading, AT (pretreated with Si69) was found to have better reinforcing effect on SBR than carbon black SRF with particle size 60–100 nm and even than N330 with particle size 26–30 nm to some extent. Meanwhile, the cost of AT/SBR composites is pretty low.