Cationic Polymerization of Cyclic Ethers Initiated by Macromolecular Dioxolenium Perchlorate

Abstract

Cationic polymerization of tetrahydrofuran (THF) with 2-methyl-1,3dioxoleum perchlorate proceeded as a living system without chain transfer and termination, and the initiation reaction was shown to be the bonding mechanism. Poly-THF with terminal dioxolenium perchlorate group was synthesized from poly(tetramethylene glycol) by stepwise reaction with adipoyl chloride, ethylene bromohydrin, and silver perchlorate. The quantitative formation of macromolecular dioxolenium salt was proved from the polymerization behavior of the THF. Polymerization of 3,3-bischloromethyloxetane by the initiator yielded block copolymer, and no chain-transfer reaction except the termination reaction was observed. Polymerization of 7-oxabicyclo[2.2.l]heptane by the initiator yielded homopolymer as well as block copolymer, and a significant amount of chain transfer reaction was observed. Polymerizatian of dioxolane and tetraoxane by the initiator yielded little block copolymer, demonstrating the different mechanism of the initiation reaction in the case of cyclic formals.

Photoinduced living cationic polymerization of tetrahydrofuran(IV): Syringe method

“…Living polymers have been the subject of extensive studies because living polymer systems enable us to synthesize monodispersed1 and terminally functional polymers,2, 3 block copolymers by sequential polymerization,4, 5 block copolymers by terminal functionalization followed by polymerization,6 block copolymers by an ion‐coupling reaction, and graft copolymers 7…”