Cationic ring-opening polymerization of 2-isopropenyl-4-methylene-1,3-dioxolane in donative solvents
✍ Scribed by Jaekyeung Park; Nobuhiro Kihara; Takeshi Endo
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 269 KB
- Volume
- 197
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
2‐Isopropenyl‐4‐methylene‐1,3‐dioxolane (1) undergoes cationic polymerization in donative solvents without crosslinking to afford poly(ether‐ketone) 2 having two unitstructures. When solvents having medium donor number (DN = 14,1–17,1), such as acetonitrile, dioxane, ethyl acetate, and propylene carbonate, were used, 2 was obtained in high yields. When solvents having DN (>19,2), such as diethyl ether, DMF, and DMAc, were used, the rate of polymerization decreased considerably, although polymerization proceeded even in the most donative solvent, DMAc (DN = 27,8). The ratio of the unit‐structures was independent of the solvent used. When ethanol was used as the solvent, ethoxyacetone and methacrolein were obtained instead of 2. It was concluded that hard nucleophiles such as ethanol attack at the α′‐position of terminal oxyallyl cation, while soft nucleophiles such as monomer 1 attack at the α‐or γ‐position.
📜 SIMILAR VOLUMES
Carbon black-supported sulfuric acid or BF 3 ⅐Et 2 O-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 u
## Abstract The methylene derivatives of 1,3‐dioxolane were proved to yield homo‐ and binary or ternary copolymers via free‐radical polymerization, depending on initiation type and reaction conditions. While different authors reported experimental data on these compounds, no explanation of such pol