Novel Dual Phase Coupling Agent for Silica/Carbon Black Hybrid Filler Containing Rubber Compounds

Fillers have important role in improving the dynamic performance of rubber compounds. Silica and carbon black possesses their own advantages. Hence, silica/CB blend is popular choice as a filler in rubber composites to achieve synergistic effects. Improvement in rubber-filler interaction and reduced filler-filler interaction leads to lower viscoelastic loss. Silane coupling agents are widely used in silica filled compounds to improve rubber-filler interactions. Very few studies are existing in literature on coupling agents for CB filled system.  This study investigates novel Polybutadiene-graft-poly(pentafluorostyene-co-trialkoxy(4-vinylphenethyl)silane)  [PB-g-P(PFS-co-StSi(OR)₃] as a dual phase coupling agent for silica/CB hybrid filler systems. The silane in the backbone covalently bonds with silica particles and pentaflouorostyrene moiety couples with carbon black via π-π interactions. The coupling reactions are studied using FTIR and solid state NMR. It is anticipated that this dual coupling capability will lead to improved viscoelastic properties over traditional silane coupling agents.