Radiation transformations of polyvinyl alcohol in aqueous solution

Some macroscopic effects of ionizing radiation on the cross-linking of polyvinyl alcohol (PVA) in aqueous solutions have been reported indicating indirect action mainly through the reactions of *OH radicals with PVA macromolecules. Experimentally obtained values of s+√s have been subjected to computer analysis on the basis of modified Charlesby-Pinner equation. Radiation yields of crosslinking have been calculated using a new ROCH equation. Radiation transformations of PVA leading to its crosslinking or degradation have been investigated by means of pulse radiolysis connected with the measurements of light absorption and light scattered intensity (LSI). Time scale of the transformations as well as rate constants of reactions proceeding in irradiated solutions in the presence and absence of oxygen have been determined. (author) 12 refs.; 3 figs