Highly soluble and colorless fluorinated poly(ether imide)s based on 4,4’-(2,5-tolylenedioxy)diphthalic anhydride and trifluoro methyl-substituted aromatic bis(ether amine)s

Abstract

A series of novel fluorinated poly(ether imide)s (PEIs) IVa-h were synthesized from 4,4'-(2,5-tolylenedioxy)diphthalic anhydride (I) and various trifluoromethyl-substituted aromatic bis(ether amine)s (IIa-h) via a conventional two-step method with thermal or chemical imidization of the precursor poly(amic acid)s. These PEIs were readily soluble in a variety of organic solvents; they were soluble with a concentration higher than 10% in amide-type polar solvents, ether type solvents, and chlorinated hydrocarbons. The solution-cast films showed a high optical transparency and low color intensity, with an ultraviolet-visible absorption edge of 371-377 nm and low b* values (a yellowness index) of 4.9-7.5. These films were strong and tough with tensile strength of 90-103 MPa. They exhibited glass-transition temperatures (T g ) in the range of 207-293 o C, with 10% weight loss temperature in excess of 500 o C in air or nitrogen atmosphere. They also showed low-dielectric constants (2.95-3.37 at 1 MHz) and low moisture absorption (0.20-0.67 wt %).