K. Sugiyama, Takashi Ishizone, A. Hirao
Dec 1, 1995
Citations
0
Influential Citations
11
Citations
Journal
Acta Polymerica
Abstract
Anionic polymerizations of 2-, 3-, and 4-fluorostyrenes (2-, 3-, and 4-FSt) were carried out at -78 °C in THF with see-butyllithium, oligo(a-methylstyryl)lithium, -dipotassium, and (1,1-diphenyl-3-methyl-pentyl)lithium as initiators to give the respective polymers in quantitative yields. The propagating carbanion derived from 2-FSt is found to survive at least for 5 min at -78 °C, affording the anionic living poly(2-FSt) with predictable molecularweight and very narrow molecular weight distribution. The addition of styrene to the anionic living poly(2-FSt) in THF affords poly(2-FSt)-block-polystyrene in quantitative efficiency, indicating the high nucleophilicity of the propagating carbanion of 2-FSt. During the polymerization of3-FSt, the benzyne intermediate is formed probably due to meta-fluoro substitution to cause polymer coupling reaction. Poly(4-FSt) produced has narrow molecular weight distribution and slightly higher molecular weight than the calculated one. The results of the polymerizations of2-FSt and 4-FSt suggest that persistency of the propagating carbanionic species of 4-FSt is slightly lower than that of 2-FSt at -78 °C.