Rubber Blend of 80/20 NR/SBR Reinforced with Nanosilica and PS-encapsulated Nanosilica

摘要

In this study, rubber blend of natural rubber (NR) and styrene butadiene rubber (SBR) at 80/20 NR/SBR was reinforced with nanosilica (nSiO_2) and polystyrene-encapsulated nanosilica (PS-nSiO_2) in the latex state. The latex of PS-nSiO_2 was synthesized by in situ differential microemulsion polymerization using sodium dodecyl sulfate and azobisisobutyronitrile as the surfactant and initiator, respectively. The nanoparticles at the amount of 0.1, 0.2, 0.3 and 0.4 parts per hundred of rubber (based on dry weight of nSiO_2) were dispersed in the rubber blend compound and subsequently cured at 80℃ for 3 h to prepare rubber nanocomposites. Using this technique, nanoparticles could be well dispersed in the rubber matrix. The influences of the nSiO_2 and PS-nSiO_2 on the mechanical and thermal properties of the resulting nanocomposites were quantified and compared. It is found that the tensile properties and thermal stability of the rubber blends were improved with the appropriate amounts of the nanofillers. However, the PS-nSiO_2 exhibited reinforcing efficiency superior to nSiO_2 with the same nSiO_2 content due to the stronger rubber-filler interfacial adhesion.