Abstract: Processes for the isolation of a telechelic isobutylene polymer in a non-aqueous system to prevent the generation of waste water having a solvent dissolved therein and processes for the preparation of a telechelic isobutylene polymer having more advantageous unsaturated groups. A process for the isolation of an isobutylene polymer includes a cationic polymerization reaction in a non-aqueous system in the presence of a catalyst MX.sub.n wherein M represents a metallic atom and X may be the same or different and represents a halogen atom or a monovalent hydrocarbon group. The process comprises conducting the cationic polymerization reaction, conducting a ligand exchange reaction of said catalyst, and then removing a component containing M.

Abstract: A method of preparing a polymer containing functional groups by reacting a polymer (A) having alkenyl groups with less than 1/N mole ratio with respect to the mole number of the alkenyl group of a silicon polyhydride compound (B) having 2 to 6 hydrogen-silicon bonds in one molecule, so as to increase the molecular weight and leaving unreacted alkenyl groups remain in molecules, or if desired, by adding the silane compound (C) in the reaction system so as to react the silane compound with the remaining alkenyl group in one-point process.