Ionic transient species in irradiated poly(vinyl chloride) film

Ionic and excited species in irradiated poly(vinyl chloride) doped with aromatic admixtures: low temperature studies

“…The absorption spectra of Py species (radicals and radical ions) in PVC matrix detected at 77 K and at higher temperatures (Fig. 2a) are, in general, similar to the results obtained for gamma-irradiated samples by Torikai et al [17 -19] and by us [4] using pulse radiolysis technique. Two absorption bands: strong one at 453 nm and quite weak one at 496 nm can be ascribed to Py…”

“…1, inset). The 295 K absorption spectrum of irradiated at 77 K PVC film is quite similar to the data observed previously [4,15,16] and can be attributed to polyenyl radicals. The optical absorption spectra of PVC doped with Py irradiated at 77 K and detected at temperatures in the range 77-290 K are shown in Fig.…”

“…4) was due to the deactivation of Py singlet excited states generated in reaction (7) by tunneling mechanism. The activation energy of Py •+ radical decay in the temperature range 100-200 K was found to be equal to 0.40 kJ/mol only [4]. The yield of reaction (7) for PVC-Py system is rather low because of shortage of Py…”

“…A short review of the available literature data concerning the radiolysis of PVC can be found there [4,5]. In the papers under consideration [4 -6] the primary ionic events have been investigated using pulse radiolysis technique.…”

“…Since the reactions involved are quite fast [4,5] the experiments have been performed in low temperatures range (77-290 K) using suitable techniques, i.e., absorption spectroscopy, radiothermoluminescence often applied in our laboratory for investigation of radiolysis products in polymeric systems [9 -12].…”