INVESTIGATION OF THE MECHANISM OF RADIOLYSIS OF POLYMERS CONTAINING QUATERNARY ATOMS OF CARBON

Journal Article · Sun Apr 01 00:00:00 EST 1962 · J. Polymer Sci.

DOI:https://doi.org/10.1002/pol.1962.1205816664· OSTI ID:4829852

Pravednikov, A N; Teleshov, E N; In, S; Medvedev, S S

The initial act of interaction of radiation in a polymer, irrespective of its chemical structure, is abstraction of an electron with formation of a positive ion. Neutralization of this ion by the electron leads to the formation of an excited molecule which subsequently breaks up with formation of free radicals. The pattern of changes occurring in the structure of the polymer will evidently depend upon the stabilization mechanism of these radicals. The fact that up to now the process of crosslinking during the radiolysis of polymers containing quatennary carbon atoms (polyisobutylene, poly- alpha -methylstyrene) has not been observed as well as the available data concerning the pattern of temperature dependence of the destruction rate, make it possible to draw the conclusion that, in these polymers, due to steric hindrances, the radicals formed as a result of the abstraction of side groups or hydrogen atoms react with each other with the breaking of the backbone chain of the polymer molecule. A study of the radiolysis of copolymers of styrene with alpha -methylstyrene in a swollen state showed that, in this case, because of the absence of steric hindrances, the interaction between the polymer radicals and radicals formed from the solvent results in the insertion of the solvent molecules into the polymer chains (demonstrated by a tracer technique); in this case the rate of degradation is decreased. Data obtained during the study of the radiolysis of the mixture of low molecular radioactive polyisobutylene with the conventional high molecular polyisobutylene show that interaction of radicals formed during the radiolysis of this polymer represents a kind of a disproportionation reaction accompanied by a transferal of the low molecular groups from one polymer radical to another. (auth)

• Research Organization: Karpov Inst. of Physics and Chemistry, Moscow
• NSA Number: NSA-16-023745
• OSTI ID: 4829852
• Journal Information: J. Polymer Sci., Vol. Vol: 58; Other Information: Orig. Receipt Date: 31-DEC-62
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
ALKYL RADICALS
BUTYLENE
CHEMICAL REACTIONS
CROSS-LINKING
DECOMPOSITION
ELECTRONS
EXCITATION
EXPANSION
FREE RADICALS
HYDROGEN
IONIZATION
IONS
METHYL RADICALS
MOLECULES
POLYMERIZATION
POLYMERS
POLYSTYRENE
RADIATION CHEMISTRY
RADIOLYSIS
REACTION KINETICS
SOLVENTS
STYRENE
TEMPERATURE
TESTING
TRACER TECHNIQUES