Key words: supercritical fluid impregnation, polymers, stable nitroxyl radicals, ESR spectroscopy
Peculiarities of impregnation processes of polymer matrixes (co-polymer F-42,
polyvinilchloride, polycarbonate, polymethylmetacrylate) with stable nitroxyl radicals
(2,2,6,6-tetramethyl-4-oxyperydin-1-oxyl (TEMOPO)) in supercritical carbon dioxide
are studied using ESR technique. The spatial distribution of radicals absorbed by polymer
films is shown to be close to random one; it is independent on film thickness. The mass
of radicals incorporated into polymer film (ΔM) grows with M0 — the mass of radicals
loaded to the reactor and tends to saturation at high M0 values. The maximum radical
concentrations absorbed by F-42 and PVC samples are 2.5 ⋅ 1020 and 3.5 ⋅ 1020 paramagnetic
centers per gram of polymer, correspondingly. At saturation no TEMOPO clusters in
polymer matrixes are observed and the spatial distribution of radicals remains random.
doi:10.1134/S199079311507009X