To improve the description of dispersed-reinforced composites, the determination of thermal and viscous parameters of polymer matrix is assumed. It’s has been shown that using of hypothesis of stability of relaxation activation energy for the polyfluorene in temperature range 10-200 0C allows to obtain a good accuracy of complex dynamic characteristics calculation in more wide frequency range (1…10 Hertz) than in case of Williams-Landell-Ferry’s equation.