Good dispersion of hydrophilic nanoscale silica in rubber matrix and the effects on rubber nanocomposites

Using the industrial technologies of rubber latex irradiation, preparation of nanoscale silica (SiO2) slurry, mixing irradiated rubber latex with SiO2 slurry, and the spray drying, we have prepared the ultrafine fully-vulcanized powder carboxyl styrene-butadiene rubber (UFPCSBR)/SiO2 nanocompound powder, in which the SiO2 particles and UFPCSBR particles are isolated and stuck each other. When the UFPCSBR/SiO2 nanocompound powder is mixed with crude rubber, the UFPCSBR particles are dispersed well in rubber matrix because of their good compatibility, then the SiO2 particles are also dispersed well in rubber matrix because of the carrier nature of the UFPCSBR particles during the mixing procedure, and the novel rubber/UFPCSBR/SiO2 nanocomposites are fabricated. Compared with the rubber composites prepared by mixing the crude rubber with the UFPCSBR powder and SiO2 powder one after the other, the novel UFPCSBR/SiO2 nanocompound modified rubber/ UFPCSBR/SiO2 nanocomposites have better abrasion resistance, higher tensile strength and tear strength, and lower heat build-up data. Noteworthily, the tanδ-temperature curve of the novel rubber/UFPCSBR/SiO2 nanocomposites has the second tanδ peak due to the newly generated boundary layer surrounding the SiO2 particles, increasing the tanδ values in the temperature range of 0–20°C, which is very important to the research of green tyre tread.