A Stepping Stone to Stereospecific Living Cationic Polymerization: Cationic Polymerization of Vinyl Ethers Using Iron(II) Sulfate

Stereospecific cationic polymerization of vinyl ether (VEs) using iron (II) sulfate FeSO4 was examined, especially focusing on the improvement of stereoregulation ability and the dual control of stereoregularity and molecular weight. An unprecedented reaction was induced with tBuOH; the polymerization using the alcohol involved the production of long-lived species, where the MWD curve of the obtained polymer shifted to the higher molecular weight region with the procession of the polymerization. The presence of acetal end structures with the tertbutoxy group derived from the used tBuOH was confirmed by the 1H NMR spectrum, which may be responsible for the controlled reactions. Thus, the fusion of the conventional catalytic system and initiating systems indicated the possibility of producing a new family of catalytic systems, especially for stereospecific living cationic polymerization.