The determination of nitroxide radical distributions within polypropyl
ene plaquettes containing amine stabilisers as well as other additives
, which had been irradiated under air on one surface for several month
s, have been determined by an X-band EPR-Imaging apparatus. It is show
n that the EPR Imaging technique represents a powerful tool for invest
igating the way in which the concentration inside polymers of nitroxid
e radicals changes both in time and in the space, thus providing infor
mation not easily obtainable by means of other techniques.