Polyimide–silver nanocomposite containing phosphine oxide moieties in the main chain: Synthesis and properties

New flame-retardant polyimide–silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique. A precursor such as AgNO3 was used as the source of the silver particles. Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of bis (3-aminophenyl) phenyl phosphine oxide 4 with pyromellitic anhydride 5 in the presence of iso-quinoline as base and in m-Cresol solution. The resulting composite film was characterized by FTIR spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry (TGA) and differential scanning calorimetry (DSC). The average size of the nanometer Ag particles is about 10 nm. The temperature of 5 and 10% weight loss and also the char yield at 600 °C of polyimide–silver nanocomposite 6a were higher than the pure PI 6.