Pure 1,2-addition polymers, poly(2-methylene-1,3-dioxolane), 1b, poly(2methylene-1,3-dioxane), 2b, and poly(2-methylene-5,5-dimethyl-1,3-dioxane), 3b, were prepared using the cationic initiators H 2 SO 4 , TiCl 4 , BF 3 , and also Ru(PPh 3 ) 3 Cl 2 . Small ester carbonyl bands in the IR spectra of 1
Regioselective polymerization of vinyl ketene cyclic acetal by means of cationic initiators
โ Scribed by Hiroyuki Fukuda; Mitsuo Oda; Takeshi Endo
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 260 KB
- Volume
- 15
- Category
- Article
- ISSN
- 1022-1336
No coin nor oath required. For personal study only.
๐ SIMILAR VOLUMES
Three unsubstituted cyclic ketene acetals (CKAs), 2-methylene-1,3-dioxolane, 1a, 2-methylene-1,3-dioxane, 2a, and 2-methylene-1,3-dioxepane, 3a, undergo exclusive 1,2addition polymerization at low temperatures, and only poly(CKAs) are obtained. At higher temperatures, ring-opening polymerization (RO
This article deals with the polymerization of the cyclic ketene acetals (CKAs) 2-methylene-4-phenyl-1,3-dioxolane (2), 2-methylene-4-phenyl-1,3-dioxane (3), 4,7-dimethyl-2-methylene-1,3-dioxepane (4), 2-ethylidene-4-phenyl-1,3-dioxolane (5), 2-phenylmethylene-1,3-dioxolane (6), and 2-isopropylidene-
Stable polymers were made by the cationically initiated 1,2-polymerization of cyclic ketene acetals employing heterogeneous, activated carbon-supported sulfuric acid catalysts. A methodology has been established for the preparation of the carbon black of different acidic strengths. By adjusting eith
Stable polymers were made by the cationic 1,2-polymerization of cyclic ketene acetals initiated by acid-washed glassware or acid-washed glass beads. Among several reactions possible for the very reactive cyclic ketene acetals, only the corresponding acetals of polyketene were formed. These structure
The relationship between the relative reactivities of ten cyclic ketene acetals and their structures was determined via cationic copolymerizations of eight different monomer pairs. Thus, 2-methylene-1,3-dioxolane (1) was copolymerized with 2-methylene-4-methyl-1,3-dioxolane (2), 2-methylene-4,5-dime