Abstract
A short review on the behaviour of the free radicals produced in irradiated polyethylene is presented and a consistent interpretation of the trapping of the free radicals in polymer is proposed in connection with the morphological fact of polymer crystals. All the observed behaviour of the stable free radicals of seven-line pattern can be interpreted by assuming that the radicals are trapped in the “pseudo-crystalline region” in polyethylene (probably the folding part of crystal lamella).