Radiation-chemical Method Research Articles

The Optical Absorption Spectra of Ferrocene and Biferrocene Anions Produced in the γ-Ray Irradiation by the Matrix-protection Method

Abstract The absorption spectra of the transient species produced through the one-electron reduction of ferrocene and biferrocene were determined by applying a radiation-chemical method in frozen glass matrices. The spectral shapes were assigned to ferrocene- and biferrocene-anionic species on the basis of the experimental results. In the biferrocene anion, the “intervalence transfer” band was observed at about 2050 nm.

Developing the principles of radiation graft recovery of depleted polytetrafluorethylene

A new radiation chemical method was proposed for the recovery of depleted polytetrafluorethylene. It involves radiation graft block copolymerization of a finely dispersed polytetrafluorethylene powder with tetrafluorethylene or other fluorinated monomers and their mixtures. An integral dose of several kilorad. ensures the necessary 15–30% graft conversion without any marked any amrked after-effect of breakdown. A study was made of the dependence of the rate of recovery on dose rate, monomer pressure and temperature. Physical and mechanical indices of the recovered product exceed 1·5 –3·0-fold the parameters of control mixtures. The reclaimed product is processed into monolithic units by sintering the moulded products in the free state.

The properties of solutions of graft copolymers of poly(vinyl alcohol) with polyvinyl pyridine

Graft copolymers of poly(vinyl alcohol) with polyvinyl pyridine have been obtained by the radiation chemical method and the properties of their solutions in formic acid have been studied. In solution in formic acid the graft copolymer molecules exhibit a number of specific properties, shown by viscometry, electron microscopy and sorption measurements.

Radiation chemical method of exciting thiacyclanes as inhibitors of radical polymerization

The inhibiting activity of the following compounds in the polymerization of methyl methacylate during γ-irradiation has been studied: elemental sulphur, 3,6-dimethyl-1,4,5-trithiocycloheptane (TCH), 1,3,5,7-tetramethyl-2,4,6,8-tetrathioadamantane (TTA) and 1,3,5,7-tetramethyl-2,4,6,8,9,10-hexathioadamantane (HTA). It is shown that γ-irradiation causes an increase in the activity of the inhibiting additions which is connected with radiolysis of the sulphur containing compounds.

Effets des solvants sur le greffage radiochimique de la vinyl-4-pyridine dans des films de polytetrafluoroethylene

Grafting of 4-vinylpyridine into the depth of PTFE films was studied using the direct radiation chemical method and solutions of monomer in either methanol or pyridine. In methanol solutions, the grafting rate is maximum for monomer concentrations of 60–85 per cent. In pyridine solutions, the rate of grafting steadily increases with monomer content. The extent of swelling of the grafted films in water is greater the longer the grafted branches. These various results are discussed.

Experimental verification of the radiation-chemical method for producing tetrachloroalkanes

Experimental verification of the radiation-chemical method for producing tetrachloroalkanes

Fluctuation of lubrication film thickness at table slideways of surface grinding machines : SHIOZAKI, S., NAKANO, Y. Bulletin of the Japan Society of Mechanical Engineers, Vol 12, No 53 (1969) pp 1212–1222

A new radiation chemical method was proposed for the recovery of depleted polytetrafluorethylene. It involves radiation graft block copolymerization of a finely dispersed polytetrafluorethylene powder with tetrafluorethylene or other fluorinated monomers and their mixtures. An integral dose of several kilorad. ensures the necessary 15–30% graft conversion without any marked any amrked after-effect of breakdown. A study was made of the dependence of the rate of recovery on dose rate, monomer pressure and temperature. Physical and mechanical indices of the recovered product exceed 1·5 –3·0-fold the parameters of control mixtures. The reclaimed product is processed into monolithic units by sintering the moulded products in the free state.

Bonding dry film lubricants : PAULUS, G. Machine Design, Vol 41, No 30 (Dec 1969) pp 68–73

A new radiation chemical method was proposed for the recovery of depleted polytetrafluorethylene. It involves radiation graft block copolymerization of a finely dispersed polytetrafluorethylene powder with tetrafluorethylene or other fluorinated monomers and their mixtures. An integral dose of several kilorad. ensures the necessary 15–30% graft conversion without any marked any amrked after-effect of breakdown. A study was made of the dependence of the rate of recovery on dose rate, monomer pressure and temperature. Physical and mechanical indices of the recovered product exceed 1·5 –3·0-fold the parameters of control mixtures. The reclaimed product is processed into monolithic units by sintering the moulded products in the free state.

Condensation of aryl monoamines with methylene dichloride

The spectra of the light (volatile) radiolysis products of polymers had similar structures, but differed with respect to steric configuration (cisand trans-polyisoprenes, cisand trans-polybutadiene), without differing in any other respect. None of the polymers used in our investigation had radiolysis products with the same spectrum as tha t of other amongst them (with the exception of cisand trans-isomers). The radiation-chemical method can be used, like the pyrolytic [3, 4], in a qualitative identification of polymers. The outstanding feature of the radiation-chemical method is the high sensitivity with respect to the hydrocarbon substituents present in the main chain.

Preparation et proprietes de quelques membranes semi-permeables obtenues par greffage de films de polytetrafluoroethylene dans leur masse

PTFE membranes with acrylic acid grafted into their mass have been prepared by the direct radiation chemical method. The influence of various parameters (PTFE film thickness, dose and intersity of radiation, monomer concentration, etc.) on the reaction has been studied. The following properties of the resulting membranes have been examined: ion exchange capacity, swelling in water, electrical resistance, thermal stability, Vinyl-4-pyridine has also been grafted into the mass of PTFE films.