A novel silicone rubber was prepared by crosslinking silylstyrene-oligomer containing -SiH groups with divinyl-polydimethylsiloxane using Karstedt’s catalyst at room temperature. Membranes cast from this silicone rubber were found capable of separating chlorinated hydrocarbons and aromatics from water containing trace amount of the organics through pervaporation (PV). Synthesis of this silylstyrene-oligomer, crosslinking it to divinyl-polydimethylsiloxane to produce the silicone rubber and preparation of membranes from this rubber are discussed. PV test results are presented.