A variety of poly(<i>m</i>‐benzamide)s with low polydispersities from inductive effect‐assisted chain‐growth polycondensation

Abstract

Abstract Chain‐growth polycondensation of 3‐(alkylamino)benzoic acid alkyl esters 1 was investigated for obtaining poly( m ‐benzamide)s with defined molecular weights and low polydispersities. Polymerization conditions were first studied to find that ethyl 3‐(octylamino)benzoate ( 1b ) polymerized in a chain polymerization manner in the presence of lithium 1,1,1,3,3,3‐hexamethyldisilazide (LiHMDS) as a base and phenyl 4‐methylbenzoate ( 2b ) as an initiator in THF at 0 °C. The molecular weight of the polymer was controlled by the feed ratio of monomer to initiator. The polymerization of 1c – i with a variety of N ‐alkyl groups was then carried out under the established conditions to yield well‐defined poly( m ‐benzamide)s, which showed higher solubility than those of the corresponding poly( p ‐benzamide)s. Furthermore, the 4‐octyloxybenzyl group on the amide nitrogen in poly 1i was removed by treatment with trifluoroacetic acid (TFA) to give N ‐unsubstituted poly( m ‐benzamide) (poly 1j ) with a low polydispersity, which is soluble in DMAc and DMSO, contrary to the para‐substituted counterpart. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4990–5003, 2006