Ionic liquids as coagents for sulfur vulcanization of butadiene–styrene elastomer filled with carbon black

Abstract

The aim of this work was to study the activity of several alkylimidazolium salts of bis(trifluoromethylsulfonyl)imides to obtain a very fast vulcanization of the butadiene–styrene (SBR) elastomer. Ionic liquids (ILs) such as alkylimidazolium salts with ethyl-, propyl-, butyl-, hexyl-, decyl-, dodecyl-, and hexadecyl chains in the cation together with nanosized zinc oxide are used to develop elastomer composites with very short vulcanization time and a reduced amount of vulcanization activator. In this article, we discuss the effect of the ILs with respect to the length of alkyl chain in their cation on the vulcanization kinetics of rubber compounds. The influence of ILs on the crosslink density as well as the mechanical properties of the vulcanizates and their resistance to thermo-oxidative and UV aging were also studied. ILs resulted in a shortened optimal vulcanization time and reduced the onset vulcanization temperature compared to zinc oxide containing rubber compound. This is very important from a technological point of view. A considerable increase in the crosslink density of vulcanizates was also observed.