CHAIN-BREAKING REACTIONS IN THE COURSE OF ISOPRENE POLYMERIZATION WITH ORGANOSODIUM INITIATORS

Molar mass characteristics of polymers obtained in various solvents by anionic polymerization of isoprene initiated with an hydrocarbon-solu ble organosdium initiator that does not contain polar substances are s tudied. Chain transfer to solvent is found for polymerization in tolue ne and xylene. Number-average molar masses of the polymers obtained in heptane and benzene are shown to increase linearly with increasing co nversion and to correspond to those characteristic of the living chain s. Evidence of chain transfer to polymer is also obtained. The effect of polar additives on the process under study is discussed.