Synthesis and properties of novel fluorinated polynaphthalimides derived from 1,4,5,8-naphthalenetetracarboxylic dianhydride and trifluoromethyl-substituted aromatic bis(ether amine)s

摘要

A series of novel fluorinated polynaphthalimides (PNI_s) (2a-g) were synthesized from I,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and trifluoromethyl (CF_3)-substi tuted aromatic bis(ether amine)s (la-g) by high-temperature solution polycondensation in m-cresol using isoquinoline as catalyst. Almost all the PNI_s were readily soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAc) and could be solution-cast to transparent and tough films with high tensile strengths. The PNI_s exhibited high thermal stability, with glass-transition temperatures of 262-383 °C, I0% weight loss temperatures above 528 °C in nitrogen or air, and char yields at 800 °C in nitro gen higher than 50%. In comparison with analogous PNI_s without the -CF3 substituents, these fluorinated PNI_s revealed an enhanced solubility and better film-forming capability.