Improving thermal conductivity of styrene-butadiene rubber composites by incorporating mesoporous silica@solvothermal reduced graphene oxide hybrid nanosheets with low graphene content

Styrene-butadiene rubber (SBR) composites with enhanced thermal conductivity (TC) were prepared, by incorporating mesoporous silica@reduced graphene oxide (mSiO2@rGO) hybrid nanosheets. The mSiO2@rGO with sandwich structure is composed of rGO (0.50 wt%) coated with mSiO2. The sandwich and mesoporous features of mSiO2@rGO were clearly characterized. Compared to rGO and mSiO2, the mSiO2@rGO shows synergistic effects on TC enhancement. The incorporation of 3 per hundred rubber (phr) mSiO2@rGO increased the TC of SBR composites to 0.424 Wm−1K−1, which was about 183% of the TC of neat SBR (0.232 Wm−1K−1). Moreover, compared to the reported silica@graphene hybrid, mSiO2@rGO has mesoporous framework with pore sizes about 8.9 nm. The mSiO2 coating on rGO acts as functional block which could impede the aggregation of rGO, decrease the modulus mismatch between rGO and SBR, and increase the interface interaction between rGO and SBR.