SYNTHESIS AND CHARACTERIZATION OF A NOVEL 3F-BASED FLUORINATED MONOMER FOR FLUORINE-CONTAINING POLYIMIDES

A novel '3F' fluorinated diamine monomer based on trifluoroacetophenon e was synthesized via a straightforward, high yielding two-step proced ure. Trifluoroacetophenone was reacted with 4-nitrophenyl phenyl ether to yield the 3F-dinitro compound, which was subsequently reduced to a fford the fluorinated diamine, minophenoxy)phenyl]-1-phenyl-2,2,2-trif luoroethane (3FEDAM). New amorphous and semicrystalline polyimides bas ed on 3FEDAM were prepared and characterized by differential scanning calorimetry, thermogravimetric analysis and wide-angle X-ray scatterin g (WAXS). In particular, the 3FEDAM-pyromellitic anhydride-phthalic an hydride material exhibited a glass transition temperature of 308 degre es C and a melting temperature of 476 degrees C which are quite simila r to the values reported for '6F'-based systems. The semicrystalline n ature was confirmed by WAXS analysis, and is consistent with the excel lent solvent resistance observed for these polyimides.