tert‐Butyl Esters as Potential Reversible Chain Transfer Agents for Concurrent Cationic Vinyl‐Addition and Ring‐Opening Copolymerization of Vinyl Ethers and Oxiranes

tert ‐Butyl esters are demonstrated to function as chain transfer agents (CTAs) in the cationic copolymerization of vinyl ether (VE) and oxirane via concurrent vinyl‐addition and ring‐opening mechanisms. In the copolymerization of isopropyl VE and isobutylene oxide (IBO), the IBO‐derived propagating species reacts with tert ‐butyl acetate to generate a copolymer chain with an acetoxy group at the ω‐end. This reaction liberates a tert ‐butyl...