Elucidating the role of clay-modifier on the properties of silica- and silica/nanoclay-reinforced natural rubber tire compounds

Organoclay (OC) is one of the potential secondary fillers to be applied in silica-reinforced rubber compounds for tire applications. Commercial OC contains a large proportion of surface modifier, i.e., dimethyl dihydrogenated tallow ammonium chloride (2HT) type, that has an influence on the compound properties. To elucidate the effect of 2HT on the properties of silica-Natural Rubber (NR) compounds, a silica-only system, silica/OC, and silica/montmorillonite (MMT)/2HT added in situ during mixing, were comparatively studied. Irrespective in which form 2HT is added, it has potential to further enhance the performance of silica-NR compounds. Incorporation of 2HT suppresses filler flocculation and improves processability. Overall, the silica-only filled compound shows better mechanical properties than the silica/clay dual filler systems. The use of a small amount (2.4?4.7 phr) of 2HT improves 300% modulus, tear strength and abrasion resistance. The silica/OC gives better mechanical properties than the silica/MMT/2HT. With the optimum content of 2HT, a higher tan 8 at ?20 ?C and lower tan 8 at 60 ?C can be achieved, all showing the beneficial potential of utilization of the modifying agent to improve wet traction and rolling resistance of silica-based tire tread compounds.

Automated summary

The addition of dimethyl dihydrogenated tallow ammonium chloride (2HT) to silica-Natural Rubber (NR) compounds has been found to improve performance, suppress filler flocculation, enhance processability, and contribute to better mechanical properties.