Radiation Chemical Conversions in Fluorine Containing Elastomers under Different γ-Irradiation Conditions

1974 ◽  
Vol 47 (2) ◽  
pp. 282-284 ◽  
Author(s):  
A. B. Kryukova ◽  
A. S. Kuz'minskii ◽  
N. S. Gilinskaya ◽  
F. A. Galil-Ogly ◽  
G. A. Sankina
Keyword(s):  
Stressed State ◽  
Vinyl Ether ◽  
High Temperatures ◽  
Vinylidene Fluoride ◽  
Chemical Crosslinking ◽  
Γ Irradiation ◽  
Radiation Chemical ◽  
Γ Radiation ◽  
Copolymer 1

Abstract Rates of radiation chemical crosslinking and scission of fluorine containing elastomers based on copolymers of vinylidene fluoride with trifluorochloroethylene (Copolymer 1), with hexafluoropropylene (Copolymer 2), and with a perfluoroalkyl vinyl ether (Copolymer 3) and also the behavior of their radiation vulcanizates in the stressed state at high temperatures are determined both by the type of polymer and by the irradiation conditions. Crosslinking rates of Copolymers 2 and 3 are higher than those of Copolymer 1; oxygen of the air inhibits crosslinking by γ-radiation; by irradiation in the presence of oxygen of the air, the sol fraction is 8–10 times higher than in its absence, Copolymer 3 vulcanizates obtained by irradiation in the absence of air appear to be optimal.

γ-Irradiation of N-vinylpyrrolidin-2-one and its homopolymer

1981 ◽  
Vol 34 (7) ◽  
pp. 1413 ◽  
Author(s):  
JE Davis ◽  
E Senogles
Keyword(s):  
Molecular Weight ◽  
Hydrogen Bonding ◽  
Main Chain ◽  
Theoretical Data ◽  
Radical Mechanism ◽  
Promoting Effect ◽  
Γ Irradiation ◽  
Radiation Chemical ◽  
Γ Radiation ◽  
Molecular Weights

The effect of γ-radiation on N-vinylpyrrolidin-2-one and its homopolymer, poly(N-vinylpyrrolidin-2-one), has been investigated. With N-vinylpyrrolidin-2-one, polymerization occurs by a radical mechanism and the presence of water has been shown to have a promoting effect on the reaction, giving both increased polymerization rates and molecular weights. This has been primarily attributed to an enhancement of N- vinylpyrrolidin-2-one reactivity through hydrogen bonding. In contrast, irradiation of N-vinylpyrrolidin-2-one in the presence of organic solvents leads to lower polymerization rates and lower molecular weights than with the undiluted monomer. ��� Poly(N-vinylpyrrolidin-2-one) primarily crosslinks on being irradiated. Gel fractions have been determined as a function of radiation dose and the results shown to be consistent with the theoretical data derived by Inokuti for a polymer with an initial molecular weight distribution of the Schulz-Zimm type. This leads to values for the radiation chemical yields of crosslinks and main chain scissions, G(X) and G(S), of 0.13�0.03 and 0.02�0.01, respectively, at 0°C.

γ-radiation, chemical synthesis of Ce3+: Gd2Si2O7/SiO2 nanocomposite

2021 ◽  
pp. 109758
Author(s):  
S. Ladjouzi ◽  
L. Guerbous ◽  
F. Bensuici ◽  
G. Bendiba
Keyword(s):  
Chemical Synthesis ◽  
Radiation Chemical ◽  
Γ Radiation

The effect of radiation-chemical crosslinking of polyethylene on its capacity to form autohesion bonds during seam welding

1971 ◽  
Vol 13 (1) ◽  
pp. 105-113 ◽  
Author(s):  
L.V. Vakula ◽  
V.I. Mishustin ◽  
V.H. Gorchakova ◽  
S.S. Voyutskii
Keyword(s):  
Chemical Crosslinking ◽  
Radiation Chemical ◽  
Seam Welding

Effects of initial concentration and irradiation dose to degradation of di butyl phthalate from phosphoric acid (30 % P2O5)

2018 ◽  
Vol 106 (11) ◽  
pp. 909-916
Author(s):  
Louisa Bounemia ◽  
Abdelhamid Mellah
Keyword(s):  
Organic Matter ◽  
Phosphoric Acid ◽  
Optimal Recovery ◽  
Γ Irradiation ◽  
Γ Radiation ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics ◽  
Butyl Phthalate

Abstract The pretreatment of the phosphoric acid is a stage of utmost importance leading to an optimal recovery of the uranium present in this acid. To this end, the degradation of the organic matter which obstructs considerably this recovery was tested by γ irradiation. This study lies within the scope of the radiation/matter interaction; concerning the use of the γ irradiator as proceed of phosphoric acid purification by the degradation of di butyl phthalate (DBP). Studies of the interaction of γ radiation with phosphoric acid solutions polluted by an organic matter concern the study of the influence of some parameters such as: dose rate (0.5–35 kGy), initial concentration (50–500 mg/L) of the pollutant, pH and % in P2O5 on the degradation of organic matter by γ irradiation. The reactions followed pseudo first order kinetics for different initial concentrations. The results made it possible to say that the degradation of di butyl phthalate by γ irradiation is dependent on the amount of the concentration of DBP and pH. The G-values decreased with absorbed doses, and increased with higher initial concentrations.Purification of phosphoric acid by γ radiation does not degrade the quality of this acid.

Effect of γ-irradiation on the molecular–topological structure of a copolymer of tetrafluoroethylene and perfluoro(propyl vinyl ether)

2017 ◽  
Vol 51 (3) ◽  
pp. 151-155
Author(s):  
Yu. A. Olkhov ◽  
S. R. Allayarov ◽  
M. Yu. Tashmetov ◽  
D. A. Dixon
Keyword(s):  
Vinyl Ether ◽  
Topological Structure ◽  
Γ Irradiation

Efficient monitoring of dosimetric behaviour for copper nanoparticles through studying its optical properties

2019 ◽  
Vol 107 (6) ◽  
pp. 523-529 ◽  
Author(s):  
Mohamad Bekhit ◽  
Asmaa Sobhy ◽  
Zakaria I. Ali ◽  
Sameh M. Gafar
Keyword(s):  
Copper Nanoparticles ◽  
Metal Ion ◽  
Copper Ions ◽  
Dose Range ◽  
Ion Concentration ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
High Dose ◽  
Γ Irradiation ◽  
Γ Radiation

Abstract A novel high-dose dosimeter based on γ radiation reduction of copper ions and formation of copper metal inside polymer matrix were investigated. γ radiation induced synthesis of copper nanoparticles (CuNPs) in poly vinyl alcohol films were studied by UV-Visible Spectrophotometer, X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The optical absorption spectra showed that the Cu/PVA nanocomposite films have surface plasmon resonance (SPR) of copper nanoparticles which depending on irradiation doses. Upon γ irradiation these films turns its color from faint blue to deep reddish brown depending on metal ion concentration. The XRD pattern and FTIR spectrum confirm the formation of the CuNPs. The response of Cu/PVA nanocomposite dosimeters depends on both the irradiation doses and concentration of copper precursor. The dose range for these films was from 50 to 650 kGy, revealing its important applications for high dose dosimetry. Cu/PVA nanocomposites films exhibit good post-irradiation stability in dark and light.

Die Reaktionen des weißen Phosphors mit Dimethyldisulfid unter γ-Bestrahlung

1968 ◽  
Vol 23 (7) ◽  
pp. 911-915 ◽  
Author(s):  
M. Scheffler ◽  
H. Drawe ◽  
A. Henglein
Keyword(s):  
Room Temperature ◽  
White Phosphorus ◽  
Red Phosphorus ◽  
Radiation Chemical ◽  
Γ Radiation ◽  
Chain Processes

Trimethylthiophosphite and red phosphorus are formed when solutions of white phosphorus in dimethyldisulfide are exposed to γ-radiation. The red phosphorus has a high content of CH3S groups. It is very reactive and can be converted into trimethylthiophosphite upon further irradiation in dimethyldisulfide suspension. Both the formation of red phosphorus from white phosphorus and the formation of trimethylthiophosphite from red phosphorus are chain processes. The radiation chemical yields are of the order of several 100 molecules/100 eV at room temperature.

ESR study of radiation-chemical crosslinking of polyvinylidene fluoride in presence of imide additives

1985 ◽  
Vol 27 (3) ◽  
pp. 553-562
Author(s):  
I.I Migunova ◽  
A.I Mikhaikov ◽  
M.D Pukshanskii ◽  
V.S Ivanov ◽  
I.M Barkalov
Keyword(s):  
Polyvinylidene Fluoride ◽  
Chemical Crosslinking ◽  
Radiation Chemical
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