Synthesis and characterization of novel fluorinated pyridine-based polyimides

New pyridine-containing polyimides based on fluorinated γ-Х-pyridylenediamines (X = H, Cl, NH2, O-linkage) and dianhydride 6FDA were prepared by one-step polycondensation in benzoic acid melt. Molecular weight of the polymers enlarges with an increase of nucleophilicity of the pyridylenediamines and solubility of the macromolecules in the reaction medium. 4,4′-Oxydianiline was used as a co-monomer to prepare high-molecular pyridine-containing PI films with good mechanical properties. The polyimides and co-polyimides obtained are soluble in amide solvents, have good thermal and thermooxidative characteristics. Parameters of the polyimides pyrolysis, which provide consecutive elimination of different elements, were found.