Synthesis and characterization of aromatic polyamides derived from new phenylated aromatic diamines

Abstract

Four new phenylated aromatic diamines, 1,4-bis(4-amino-3,5-diphenylphenyl)benzene (1a), 1,3-bis(4-amino-3,5-diphenylphenyl)benzene (1b), 1,4-bis(4-aminophenyl)-2,3,5-triphenylbenzene (2a), and 1,4-bis(4-aminophenyl)-2,3,5,6-tetraphenylbenzene (2b) were synthesized and polymerized with terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC). All the polyamides showed high thermal stability with 5% weight-loss temperatures in the range of 466–524°C in air or nitrogen, and no melting peak below their decomposition temperatures. The polymers containing m-catenation had glass transition temperatures in the range of 275–349°C, and were soluble in N-methyl-2-pyrrolidone (NMP). The rigid rod-like polyamides consisting all para-oriented linkages showed no clear glass transition. In the rod-like polymers, polymer 2a/TPC showed good solubility in NMP, and preliminary optical microscope observation for the 20% solution showed an anisotropic property. © 1992, The Society of Polymer Science, Japan. All rights reserved.