16969-19-0Relevant articles and documents
Living and Alternating Cationic Copolymerization of o-Phthalaldehyde and Various Bulky Enol Ethers: Elucidation of the "Limit" of Polymerizable Monomers
Hayashi, Keisuke,Kanazawa, Arihiro,Aoshima, Sadahito
, p. 1365 - 1375 (2022/02/23)
Cationic copolymerization of various bulky enol ethers, which have been difficult to homopolymerize and/or copolymerize, was shown to proceed when o-phthalaldehyde (OPA) was used as a comonomer. A series of enol ethers with various substituents on the β-carbon was synthesized from aliphatic aldehydes and alcohols. The relationships between the structures of the enol ethers and the copolymerization behavior were systematically investigated. As a result, monomers with one or two methyl and/or primary alkyl groups on the β-carbon were found to undergo alternating copolymerization with OPA. Moreover, living cationic copolymerization of enol ethers and OPA yielded alternating copolymers under appropriate polymerization conditions. To elucidate the limit of polymerizable monomers, the copolymerization of very bulky enol ethers such as β-t-butyl- or norbornenylidene-type monomers with OPA was also examined. OPA was found to be copolymerizable even with such very bulky monomers, indicating that the unique reactivity of the OPA-derived propagating carbocation with small steric hindrance is the key factor for successful copolymerization.
