Novel ortho‐linked fluorinated poly(ether‐imide)s based on 2,2′‐substituted 1,1′‐binaphthyl units

In this research, a new fluorinated diamine based on 2,2′‐substituted 1,1′‐binaphthyl units, 2,2′‐bis(2‐amino‐4‐trifluoromethylphenoxy)‐1,1′‐binaphthyl (AFPBN) was synthesized and then used to prepare the corresponding ortho‐linked poly(ether‐imide)s via chemical polyimidization with several aromatic carboxylic dianhydrides. The resulting poly(ether‐imide)s were fully characterized by FT‐IR, NMR, viscosity measurements, gel‐permeation chromatography, UV–vis, X‐ray diffraction, organo‐solubility, thermogravimetric analysis (TGA), and differential scanning calorimetry. Probing optical behavior of the colorless films prepared from these poly(ether‐imide)s demonstrated that they possess a high degree of optical transparency, and UV–visible absorption cut‐off wavelength values were found to be in the range of 404–471 nm. The resulting polymers exhibited excellent organo‐solubility in polar solvents such as dimethylformamide, dimethyl sulfoxide, pyridine, and even tetrahydrofuran. To investigate the heat stability of the samples, their thermograms obtained from TGA were plotted, and for example, it is found that the 10% weight loss temperature of representative polymer AFPBN/3,3′,4,4′‐benzophenonetetracarboxylic dianhydride occurred at 532°C in nitrogen. These poly(ether‐imide)s had glass‐transition temperatures (T_g's) up to 280°C. Two previously prepared analogues of AFPBN, i.e. nonfluorinated diamine DAM1 and para‐linked fluorinated diamine DAM2 used to prepare the corresponding poly(ether‐imide)s, were also considered to compare the results obtained. Copyright © 2012 John Wiley & Sons, Ltd.