Impact of ionic liquids on the processing and photo-actuation behavior of SBR composites containing graphene nanoplatelets

The effects of butylpyridinium bromide-based ionic liquids (ILs) on the vulcanization kinetics, mechanical properties and photo-actuation ability of styrene-butadiene rubber (SBR) composites filled with graphene nanoplatelets (GnPs) were investigated. Two different ILs, 1-butylpyridinium bromide (BBP) and 4-methyl-1-butylpyridinium bromide (BMBP), were introduced into rubber compounds. The methodology of IL incorporation into the rubber compounds was studied as well. The ILs were added either directly as a single component or after immobilization onto the GnPs surface. High values of the modulus and tensile strength, which are important mechanical properties, were observed for the composites filled with immobilized BMBP. Freely dispersed BBP resulted in composites with the fastest scorch time, highest thermal and electrical conductivity, and best photo-actuation response of 0.230 mm.