Effects of liquid polyisoprene and magnesium oxide on the mechanical properties of styrene‐butadiene rubber/carbon nanotubes composite

Effects of liquid polyisoprene (LIR) and magnesium oxide (MgO) on the mechanical properties of styrene‐butadiene rubber/carbon nanotubes (SBR/CNT) composite were studied. After LIR was added into SBR/CNT compound, the curing rate and torque decreased, and the Payne effect became less pronounced. The presence of LIR in SBR/CNT vulcanizate could increase the elongation at break, decrease the moduli at given extensions, the stress relaxation factor, and the degree of the stress softening effect. The presence of LIR and MgO in SBR/CNT could increase the moduli at given extensions and the degree of the stress softening effect. CNT could be well dispersed in SBR/CNT/LIR/MgO composite. The Raman characteristic peaks of CNT shifted to low wavenumber with the addition of LIR and MgO into SBR/CNT. LIR and MgO affected the dynamical mechanical properties of SBR/CNT vulcanizate, increasing the elastic modulus, glass transition temperature, and tan δ value at 0°C. POLYM. COMPOS., 39:E765–E771, 2018. © 2016 Society of Plastics Engineers