Dynamics of excess free volume in semicrystalline PEEK studied by positron annihilation

The dynamical behavior of the free volume creation and its relaxation in the amorphous regions of two-phase PEEK were monitored during isothermal crystallization as a function of annealing time . The kinetics of the isothermal crystallization was analyzed by the Avrami equation. The developement of the relative crystallinity, mean free-volume hole size and relative free volume fraction were obtained.