Investigation of γ-irradiated polyvinylidene fluoride and its acute toxicity

Autor: Matthew P. Confer, E. N. Klimanova, David A. Dixon, Sergei Demidov, Uguljan Yu. Allayarova, Denis V. Mishenko, Sadulla R. Allayarov
Rok vydání: 2021
Předmět:
Zdroj: Journal of Fluorine Chemistry. 251:109885
ISSN: 0022-1139
DOI: 10.1016/j.jfluchem.2021.109885
Popis: Polyvinylidene fluoride (PVDF) is an industrial polymer with many applications. The EPR spectrum of polyvinylidene fluoride (PVDF) irradiated by γ-rays at low temperature (-196°C) provides evidence for the presence of radicals formed by loss of a fluorine atom from PVDF, and polyenyl radicals. Polyenyl radicals dominate in the polymer irradiated at room temperature. Peroxide radicals formed as a result of oxidation of primary free radicals by atmospheric oxygen are observed in the EPR spectrum of a polymer irradiated in air, or when air is introduced to a polymer irradiated in a vacuum. Carbonization and oxidation of γ-irradiated PVDF were observed in the XPS spectrum. A model for polymer degradation based on correlated G3(MP2) molecular orbital theory electronic structure calculations is described. The presence of HF in the products and a low yield of products with the composition CxFyHz indicate the absence of noticeable thermal destruction of the main polymer chain upon heating to 220°C of both the initial and γ-irradiated PVDF. Although any HF released during the PVDF dehydrofluorination would be toxic, a study of the acute toxicity of γ-irradiated PVDF showed that the polymer does not exhibit toxicity after a single intragastric route of administration to mice.
Databáze: OpenAIRE