Cationic copolymerization of cyclic ketene acetals: The effect of substituents on reactivity

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

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 217 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980430)36:6<861::aid-pola1>3.0.co;2-k

✦ Synopsis

of 4-methyl-2-methylene-1,3-dioxane, 2 (M 1 ), with 2-methylene-1,3-dioxane, 1 (M 2 ); of 4,4,6-trimethyl-2-methylene-1,3-dioxane, 3 (M 1 ), with 2-methylene-1,3-dioxane, 1 (M 2 ); of 4-methyl-2-methylene-1,3-dioxolane, 5 (M 1 ), with 2-methylene-1,3-dioxolane, 4 (M 2 ); and of 4,5-dimethyl-2-methylene-1,3dioxolane, 6 (M 1 ), with 2-methylene-1,3-dioxolane, 4 (M 2 ) were conducted. The reactivity ratios for these four types of copolymerizations were r 1 Å 1.73 and r 2 Å 0.846; r 1 Å 2.26 and r 2 Å 0.310; r 1 Å 1.28 and r 2 Å 0.825; r 1 Å 2.23 and r 2 Å 0.515, respectively. The relative reactivities of these monomers towards cationic polymerization are: 3 ú 2 ú 1; and 6 ú 5 ú 4. With both five-and six-membered ring cyclic ketene acetals, the reactivity increased with increasing methyl substitution on the ring.