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The action of light of free radicals in γ-irradiated polymers
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A ~
cal bond between the two polymers has been shown ~o int~fere with the crystallization of polyhydroxypelargonate, despite the existence of ordering processes which lend a regular external appearance to the resultant structures. The absence of crystallization in the given graft copolymer does not allow of the assumption that amorphous and crystalline phases coexist within the framework of a single macromolsoule. POLYMERIZATION OF VINYL ISOMERS INITIATED BY COMPLEXES OF POTASSIUM SILANOLATES WITH LEWIS BASES M. K u c h e r a , V y s o k o m o l . soyed. 5, No. 6, 938-945, 1963.
\ POLYMERIZATION of octamethylcyclotetrasiloxanes initiated by - - S i - - O K in the presence
/
of d.iphenylamine proceeds at times more rapidly and at times more slowly than in the absence of ~phenylamine. The determinative factors in the lower or higher overall polymeri. zation rate were found to be temperature and the diphenylamine concentrations. This effect is ascribed to the formation of complexes at the active centres. Many vinyl monomers are capable of initiating the formation of complexes between -+Si--OK and anisole or dipehnylamine. Polymerization of methyl methaerylate, styrene, vinyl acetate, acrylonitrile and vinylchloride has been investigated in some detail. The polymerization rate is quite slow and the resultant macromolecules possess a high degree of polymerization. The polymers have high melting points. THE ACTION OF LIGHT OF FREE RADICALS IN F-IRRADIATED POLYMERS V. K . M i l i n c h u k a n d S. Ya. P s h e z h e t s k i i , V y s o k o m o l . s o y e d . 5: N o . 6, 946, 1963. IT HAS been found that free radicals in y-irradiatec[ polymers recombine under the action of UV light. They also undergo reversible and irreversible transformations. The effect is explained in terms of migration of the energy--absorbed by the absorbing groups of the polymers.
A ~
cal bond between the two polymers has been shown ~o int~fere with the crystallization of polyhydroxypelargonate, despite the existence of ordering processes which lend a regular external appearance to the resultant structures. The absence of crystallization in the given graft copolymer does not allow of the assumption that amorphous and crystalline phases coexist within the framework of a single macromolsoule. POLYMERIZATION OF VINYL ISOMERS INITIATED BY COMPLEXES OF POTASSIUM SILANOLATES WITH LEWIS BASES M. K u c h e r a , V y s o k o m o l . soyed. 5, No. 6, 938-945, 1963.
\ POLYMERIZATION of octamethylcyclotetrasiloxanes initiated by - - S i - - O K in the presence
/
of d.iphenylamine proceeds at times more rapidly and at times more slowly than in the absence of ~phenylamine. The determinative factors in the lower or higher overall polymeri. zation rate were found to be temperature and the diphenylamine concentrations. This effect is ascribed to the formation of complexes at the active centres. Many vinyl monomers are capable of initiating the formation of complexes between -+Si--OK and anisole or dipehnylamine. Polymerization of methyl methaerylate, styrene, vinyl acetate, acrylonitrile and vinylchloride has been investigated in some detail. The polymerization rate is quite slow and the resultant macromolecules possess a high degree of polymerization. The polymers have high melting points. THE ACTION OF LIGHT OF FREE RADICALS IN F-IRRADIATED POLYMERS V. K . M i l i n c h u k a n d S. Ya. P s h e z h e t s k i i , V y s o k o m o l . s o y e d . 5: N o . 6, 946, 1963. IT HAS been found that free radicals in y-irradiatec[ polymers recombine under the action of UV light. They also undergo reversible and irreversible transformations. The effect is explained in terms of migration of the energy--absorbed by the absorbing groups of the polymers.