화학공학소재연구정보센터
International Polymer Processing, Vol.19, No.4, 364-373, 2004
Reactive batch mixing for improved silica-silane coupling
Moisture (55 wt%) treated silica compounds, bis(triethoxysilylpropyl)disulfide(TESPD)/silica/carbon black/S-SBR was processed in a batch mixer and they were investigated with respect to the alcohol residue level in silane, the processability, the vulcanization characteristics, and the mechanical properties. Treatment of moisture on the TESPD/silica/carbon black/S-SBR compound showed a lower alcohol level than untreated material. The alcohol level was low at high drop temperatures. The probe temperatures of the moisture treated compound were lower than the drop temperature, while that of the untreated compound was higher than the drop one. The vulcanization properties of the compounds were changed by treatment of moisture and this improved the mechanical properties of the compounds. The treatment of moisture on silica surface increased the hydrolysis reaction of the alkoxy silane and the hydrolyzed silane improved the coupling reaction with the hydroxyl group on silica surface during reactive batch processing. It also reduced the rate of temperature rise during batch processing due to the latent heat of the moisture and the endothermic reaction between silica and silane. At the vulcanization stage, it seemed to further increase the coupling reaction between silica and silane. The steric hindrance theory of an alkoxy silane has to be reconsidered with a large amount of moisture treated silica/TESPD/CB/S-SBR compound system.