SYNTHESIS AND PROPERTIES OF POLYARAMIDES AND POLY(AMIDE-IMIDE)S CONTAINING 5,10-DIHYDROPHENAZINE UNITS

Novel families of aromatic polyamides and poly(amide-imide)s containin g 5,10-dihydrophenazine-based repeat units were prepared from 5,10-dih ydrophenazine (1) and its diamino-functional derivatives. Basic struct ure/property relationships and degradation behavior were investigated. Polycondensation of aromatic dicarboxylic acid chlorides with seconda ry aromatic diamines such as 5,10-dihydrophenazine or its 5,10-bis(tri methylsilyl) derivative (3) yielded only oligoaramides. In contrast, 5 ,10-bis(4-aminobenzoyl)5,1 0-dihydrophenazine (5) was applied successf ully as a new primary aromatic diamine monomer in polycondensations to afford various high molecular weight soluble polyaramides derived fro m terephthaloyl and isophthaloyl chloride as well as poly(amide-imide) s derived from 6F dianhydride(b). Tough, optically transparent films w ere prepared by solution casting of 6F poly(amide-imide)s containing 5 , 10-dihydrophenazine units. In comparison to piperazine units the 5,1 0-diyhdrophenazine units promote solubility and increase the glass tra nsition temperatures. Reduced thermal and chemical stabilities are att ributed to an easy phenazine formation. Polyaramide and poly(amide-imi de) films containing 5,10-dihydrophenazine units are photosensitive an d were degraded by means of UV irradition and laser ablation.