Polyimides derived from 1,2-bis(4-aminophenoxy)propane

The diamine 1,2-bis(4-aminophenoxy)propane, containing the flexible 1,4-dioxa-2-methylbutyl-ene unit, was synthesized. Polyimidization was carried out with 5,5′-[2,2,2-trifluoro-(trifluoromethyl)ethylidine]bis-1,3-isobenzofurandione in m-cresol employing toluene as azeotroping agent to yield a polyimide that was soluble in a variety of solvents and had an inherent viscosity of 0.84 dL/g in N,N-dimethylformamide. Poly(amic acid) formation with pyromellitic dianhydride, 4,4′-carbonyldiphthalic anhydride, and 5,5′-[ethanediylbis(oxy)]-bis-1,3-isobenzofurandione was carried out in N,N-dimethylformamide with imidization completed by heating at 160°C for 24 h under vacuum. All of the polyimides exhibited a 5% weight loss in air and in helium by 420°C.