Influence of ionic liquids on rheological behaviors of polyisoprene rubber/silica compounds

Abstract

Ionic liquids (ILs), 1-allyl-3-methyl-imidazolium chloride (AMIC) and 1-decyl-3-methyl-imidazolium chloride (DMIC), are used to pretreat hydrophilic fumed silica. Their influence on rheological responses of silica filled isoprene rubber (IR) compounds is investigated. The presence of ILs causes silica to form large agglomerates in the IR matrix, lowers bound rubber content, and prevents the formation of glassy fraction of IR chains. In the low filling compounds, ILs at low contents could lower reinforcement efficiency of silica, improve loss factor and promote the macromolecular diffusion. For the highly-filled compounds, ILs are able to improve the reinforcement efficiency on the one hand and intensify the weak strain overshoot accompanying the Payne effect on the other hand. Nevertheless, ILs do not influence strain amplification effect induced by silica.