Thermal characterization and thermal degradation of copolyimides containing fluorine and phosphine oxide

摘要: A series of copolyimides containing different ratios fluorine and phosphine oxide were synthesized. The copolymers characterized with Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis measurements. thermally stable up to 700 K exhibited glass-transition temperatures in the range 495–562 K. decreased an increase content. thermal decomposition behavior was investigated. higher contents displayed lower onset char yields. new method involving multiple-rate isotemperature used define most possible mechanism [G(α)] for reactions. overall kinetic model function these obeyed Avrami–Erofeev equation, G(α) = [−ln(1 − α)]1/m, where α is conversion degree. apparent parameters degradation processes also obtained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2139–2143,