Polyamide-imides bearing furan moieties. 1. Solution polycondensation of aromatic dianhydrydes with 2-furoic acid dihydrazides

Novel polyamide-imides containing flexible segments were synthesized from aromatic dianhydrides and various furan dihydrazides by a two-steps procedure that included ring opening polyaddition to give polyhydrazide-acids, followed by thermal or chemical cyclodehydration. The polyhydrazide-acids had inherent viscosities ranging from 0.045 to 0.11 l/g. The polyamide-imides showed good solubility in aprotic polar solvents and had inherent viscosities up to 0.070 l/g, glass transition temperatures close to 250 °C and good thermal stability up to 350 °C.