Preparation and Application of Chemically Bonded Silica Supported Calix[4]arene as Reinforced Filler in NR/BR Blend Based Rubber Compounds

Abstract

In this study, we tried to reduce polarization of silica surface by chemically bonding cholorosulfonyl calix[4]arene (CSC[4]A) and silica (Si–O–Cl) to improve dispersion between filler and elastomer. To confirm synthesis of CSC[4]A, ¹H NMR, ¹³C NMR, and IR spectrophotometry were used. Obtained composite of chemically bonded silica and CSC[4]A was characterized by TGA. Compounds (contained silica, silica and silane, silica-calix system) were prepared to investigate the effect of silica-calix system (CSC[4]A-SiO₂) on the rheological and mechanical properties of rubber compounds based on natural rubber/cis-butadiene rubber (NR/BR) blend in tire tread formulation. The rheological and mechanical properties of three samples were investigated by different devices and a surface morphology was evaluated by FESEM technique. The results revealed that the curing behavior of the compound with CSC[4]A-SiO₂ did not significantly differ from other compounds, while reversion was considerably reduced compared with that to other compounds. Also, the mechanical properties of compound with CSC[4]A-SiO₂ were improved dramatically especially in fatigue resistance.