Activated monomer cationic polymerization of 1,3-dioxepan-2-one initiated by water-hydrogen chloride

The ring-opening polymerization of 1,3-dioxepan-2-one (7CC) was carried out by water-hydrogen chloride as an initiator to obtain the corresponding polymer with the molecular weight controlled by the amount of water. A ¹H NMR spectroscopic study suggests that the chain growth in this system is based on the attack of the terminal hydroxyl group to the monomer activated with hydrogen chloride.