The reaction mechanism of irradiation induced grafting co-polymerization offluoride polymer is investigated by positron annihilation lifetAne technique. Theresults indicated that γ-irradiation induced grafting changed the structure ofcondensed state of polymer. With increasing irradiation dose
graft rate raised andthe long lifetime of positron annihilation changed significantly. It show thatirradiation- grafted reaction is mainly localized in non- crystflllite as well as interfacebetween non-crystallite and crystallite.