Relative reactivities of cyclic ketene acetals via cationic 1,2-vinyl addition copolymerization1

✍ Scribed by Liwei Cao; Zhihong Wu; Charles U. Pittman Jr.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 266 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990801)37:15<2841::aid-pola18>3.0.co;2-n

✦ Synopsis

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-dimethyl-1,3-dioxolane (3), 2-methylene-4,4,5,5-tetramethyl-1,3-dioxolane (4), 2-methylene-4-phenyl-1,3-dioxolane (5), and 2-methylene-4-(t-butyl)-1,3-dioxolane (6). Also 2-methylene-1,3-dioxane (7) was copolymerized with 2-methylene-4-methyl-1,3-dioxane (8), 2-methylene-4,4,6-trimethyl-1,3-dioxane ( 9), and 2-methylene-4-isopropyl-5,5-dimethyl-1,3-dioxane (10). The relative reactivities of these monomers are: 3 Ͼ 5 Ͼ 4 Ͼ 2 Ͼ 1 Ͼ 6; and 10 Ͼ 9 Ͼ 8 Ͼ 7. In spite of steric demands, substituents at the 4-or 5-positions in 2-methylene-1,3-dioxolane and substituents at the 4-or 6-positions in 2-methylene-1,3-dioxane serve to increase the copolymerization reactivity.