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

Abstract A series of novel fluorinated polynaphthalimides (PNIs) ( 2a – g ) were synthesized from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and trifluoromethyl (CF 3 )-substituted aromatic bis(ether amine)s ( 1a – g ) by high-temperature solution polycondensation in m -cresol using isoquinoline as catalyst. Almost all the PNIs 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 PNIs exhibited high thermal stability, with glass-transition temperatures of 262–383 °C, 10% weight loss temperatures above 528 °C in nitrogen or air, and char yields at 800 °C in nitrogen higher than 50%. In comparison with analogous PNIs without the –CF 3 substituents, these fluorinated PNIs revealed an enhanced solubility and better film-forming capability.