NR was firstly compounded with ENR, then SiO2and otheradditives were added into the NR/ENR blends and compoundedon the X(S)K-160 two-roll open mill (Zhanjiang China). The com-pounds were compression molded at 143◦C for optimum curingtime T90determined by a rheometer. The compositions of NR/silicacomposites are showed in Table 1. In the preparation of NR/silicacomposites, considering that ENR-40 has strong polar and poorercompatibility with NR, we employed ENR-25 with less oxygengroups to modify silica instead of ENR-40