title: Inductive effect-assisted chain-growth polycondensation. synthetic development from para- to meta-substituted aromatic polyamides with low polydispersities.
abstract: The polycondensation of m-(octylamino)benzoic acid esters (1) with base was investigated in order to extend the synthesis of well-defined condensation polymers from para-substituted polymers to meta-substituted ones. We expected that the aminyl anion of 2 would deactivate the ester moiety at the meta position of 2 owing to the strong inductive effect of the anion, resulting in, not self-polycondensation, but chain-growth polycondensation. The methyl ester monomer 1a polymerized with lithium hexamethyldisilazide (LiHMDS) in the presence of phenyl benzoate (3a) as an initiator at 0 degrees C to afford a polymer with a low polydispersity, but the product contained a small amount of self-condensation polymer. On the other hand, the polymerization of the ethyl ester monomer (1b) with phenyl 4-methylbenzoate (3b) proceeded through chain polymerization without self-polycondensation. The Mn values of the polymers increased linearly in proportion to the [1b]0/[3b]0 ratio, and the Mw/Mn ratios remained narrow over the entire [1b]0/[3b]0 range. Furthermore, a block copolymer of N-alkylated poly(m-benzamide) and poly(p-benzamide) with a low polydispersity was synthesized by the monomer addition method under this polymerization condition.
authors: Department of Applied Chemistry, Kanagawa University, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan.
authors: Ryuji
authors: R
authors: Sugi
authors: Akihiro
authors: A
authors: Yokoyama
authors: Taniyuki
authors: T
authors: Furuyama
authors: Masanobu
authors: M
authors: Uchiyama
authors: Tsutomu
authors: T
authors: Yokozawa