Abstract
A new method that polyamide-imides were synthesized from dihydrazide compound and aromatic tetracarboxylic acid dianhydrides, was examined. It was revealed that these resins had 5 membered-ring imide structures. Although thermal stability of these resins is somewhat lower than that of conventional polyamide-imide synthesized by way of isocyanate route, these resins have some optical characteristics, such as higher transmission and slightly lower index of refraction. Moreover it was found from TGA curves that their thermal decomposition occured in two steps and we guessed that their thermal decomposition at the first step was caused by the cleavage of N-N bond which had the lowest bonding energy in polymer chains.
