Abstract
The influences of alkoxy group number and loading method of silane coupling agents on the mechanical properties of a styrene-butadiene rubber/silica composite were reviewed. The pre-treatment method and the integral blend method were compared. In the case of mercapto-functional silane, the 200% modulus was higher in the pre-treatment than in the integral blend for dialkoxy type. However, it was higher in the integral blend than in the pre-treatment for trialkoxy type. The binding of rubber molecular chains by the silane chains on the silica surface was higher in the pre-treatment for dialkoxy type, whereas it was higher in the integral blend for trialkoxy type. In the pre-treatment for dialkoxy type, a linear silane chain formed in the case of multi-layer coverage. The silane chain entangled with the rubber chain and improved the reinforcement effect. In the integral blend for trialkoxy type, the formation of the silane network and the entanglement progressed simultaneously during the preparation process. A well entangled interfacial region was formed. The 1H pulse nuclear magnetic resonance spectroscopy was measured for the unvulcanized rubber/silica mixture. The measured relaxation time was found to be in good correlation with the 200% modulus.
