SYNTHESIS AND CHARACTERIZATION OF NAPHTHALENE-CONTAINING POLYTHIOAMIDES

New semi-aromatic polythioamides have been synthesized, based on aliph atic diamines and a new bis(dithioester) derived from 2,6-naphthalened icarboxylic acid. Polythioamides were prepared by solution polycondens ation at low temperature, in high yields and moderate to high inherent viscosities. The presence of naphthalene rings instead of benzene rin gs or aliphatic groups affected the thermal transitions in these polyt hioamides. By comparison with aliphatic or benzene polythioamides, pol ythioamides containing naphthalene revealed lower glass transition tem peratures and a tendency to form liquid crystal mesophases. Noticeable solubility improvements were also observed. (C) 1998 Elsevier Science Ltd. All rights reserved.