Cationic Polymerizations of Substituted 2-Methylene-1,3-Dioxocyclic Acetals, 2-Methylene-1,3-Dithiolane and Copolymerization of 2-Methylene-1,3-Dithiolane with 4-(t-Butyl)-2-Methylene-1,3-Dioxolane

摘要

Carbon black-supported sulfuric acid or BF_3 centre dot Et_2O-initiated polymerizations of 2-methylene-4,4,5,5-tetramethyl-1,3-dioxolane (1), 2-methylene-4-phenyl-1,3-dioxolane (2), and 2-methylene-4-isopropyl-5,5-dimethyl-1,3-dioxane (3) were performed. 1,2-Vinyl addition homopolymers of 1-3 were produced using carbon black-supported H_2SO_4 initiation at temperatures from 0 deg C to 60 deg C whereas both ring-opened and 1,2-vinyl structural units were present in the polymers using BF_3 centre dot Et_2O as an intiator. Cationic polymerizations of 2-methylene-1,3-dithiolane (4) and copolymerization of 4 with 2-methylene-4-(t-butyl)-1,3-dioxolane (5) were initiated with either carbon black-sulfuric acid or BF_3 centre dot Et_2O. Insoluble 1,2-vinyl addition homopolymers of 4 were obtained upon initiation with the supported acid or BF_3 centre dot Et_2O. A soluble copolymer of 2-methylene-1,3-dithiolane (4) and 4-(t-butyl)-2-methylene-1,3-dioxolane (5) was obtained upon BF_3 centre dot Et_2O initiation. This copolymer is composed of three structural units: a ring-opened dithioester unit, a 1,2-vinyl-polymerized 1,3-dithiolane unit, and a 1,2-vinyl polymerized 4-(t-butyl)-1,3-dioxolane unit.