Investigation of γ-irradiated polyvinylidene fluoride and its acute toxicity

Investigation of γ-irradiated polyvinylidene fluoride and its acute toxicity

•γ-irradiation of PVDF at low temperature forms backbone polyenyl radicals by loss of fluorine.•G3(MP2) calculations were used to develop a mechanism.•Carbonization and oxidation increased in air exposed γ-irradiated PVDF.•Irradiation of PVDF lowers the melting point and does not crosslink the polym...

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Bibliographic Details
Published in:Journal of fluorine chemistry Vol. 251; no. C; p. 109885
Main Authors: Allayarov, Sadulla R., Confer, Matthew P., Demidov, Sergei V., Yu. Allayarova, Uguljan, Mishenko, Denis V., Klimanova, Elena N., Dixon, David A.
Format: Journal Article
Language:English
Published: United States Elsevier B.V 01-11-2021
Elsevier
Subjects:
acute toxicity
correlated G3
correlated G3(MP2) molecular orbital theory
EPR
INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
molecular orbital theory
MP2
polyvinylidene fluoride
predicted decomposition thermodynamics
γ-irradiation
correlated G3(MP2) molecular orbital theory
EPR
predicted decomposition thermodynamics
acute toxicity
polyvinylidene fluoride
γ-irradiation
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Summary:•γ-irradiation of PVDF at low temperature forms backbone polyenyl radicals by loss of fluorine.•G3(MP2) calculations were used to develop a mechanism.•Carbonization and oxidation increased in air exposed γ-irradiated PVDF.•Irradiation of PVDF lowers the melting point and does not crosslink the polymer.•Irradiated PVDF is not acutely toxic to mice. 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. [Display omitted]
Bibliography:USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB)
University of Alabama
SC0018921; АААА-А19-119041090087-4
ISSN:0022-1139
1873-3328
DOI:10.1016/j.jfluchem.2021.109885