Synthesis of novel poly(thioether-naphthalimide)s that utilize hydrazine as the diamine

A series of bis(4-thio-1,8-naphthalic anhydride)s and the corresponding bis(N-amino naphthalimide) derivatives were synthesized from readily available compounds in high yield. A series of novel poly(thioether-naphthalimide)s, which utilized hydrazine as the diamine, were synthesized by a one-step polymerization reaction in m-cresol. Poly(thioether-naphthalimide)s with inherent viscosities of 0.57–1.73 dL/g were obtained. The polymers were soluble in CHCl3 and were determined to have high molecular weights by means of gel permeation chromatographic analysis. They were soluble in m-cresol and could be cast into tough films from m-cresol solution. The glass-transition temperature (Tg) values of the polyimides ranged from 320 to 353 °C. Polyimides from the bisphenol dianhydride, derived from 9,9-bis(4-hydroxyphenyl)fluorene, did not show a clear transition in the DSC analysis. Degradation temperatures for 5% weight loss all occurred above 430 °C in nitrogen. The series of monomers were successfully copolymerized with each other. Monomers 6a and 7a, containing the bisphenol A moiety, could also be copolymerized with perylenetetracarboxylic dianhydride. These copolymers had high Tg's and were thermally stable. The UV–vis absorption properties of the polymers were also examined.