Specificity of proton irradiation effects on polymers

Protons affect the polymers mainly through scission and cross-linking of macromolecule chains. Ionization processes at proton non-elastic scattering define these effects. One of the most important problems of radiation physics and chemistry of polymers is the dependence of radiation effects on polymers on the kind of ionizing radiation or the LET problem. Analyze of such dependence for protons and some other kinds of radiation is presented. A detailed examination of 100 MeV proton collisions in polyethyleneterephtalate (PETP, trade mark Mylar) with negligible quantity of additive, on the base of the sample heat conductivity behavior revealed an important role of atomic displacements resulting from elastic nuclear scattering of low energy ions. Such damage of polymer molecules was not obtained for other examined types of radiation, in particular, for recoil nuclei at reactor neutron irradiation and for 60Co γ-irradiation.