A novel water-swellable rubber (WSR) was prepared by blending styrene butadiene rubber (SBR) with dicumyl peroxide (DCP) and unsaturated carboxylic acid salt lithium acrylate (LiAA). The mechanical properties and water absorption behavior of WSR were studied. The results showed that LiAA was developed into polylithiumacrylate (PliAA) during the process of SBR vulcanization through in-situ polymerization, leading to the improvement of the mechanical properties and water absorption performance. The optimum usages of DCP and triallyl isocyanurate (TAIC) to attain the highest water swelling ratio for WSR were 3 and 1 phr, respectively. In addition, the tensile strength and the hardness of WSR were also enhanced by incorporating DCP or TAIC.

Keywords: water swellable rubber; in-situ polymerization; lithium acrylate; water absorption rate