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Author Fock, J. ♦ Henglein, A. ♦ Schnabel, W.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ ABSORPTION ♦ ACETATES ♦ ACRYLIC ACID ♦ ALPHA BEAMS ♦ ALPHA PARTICLES ♦ CHEMICAL REACTIONS ♦ CONFIGURATION ♦ DIAGRAMS ♦ DISTRIBUTION ♦ EFFICIENCY ♦ ELECTRONS ♦ ENERGY ♦ ENERGY RANGE ♦ EQUATIONS ♦ FREE RADICALS ♦ GAMMA RADIATION ♦ IONIZATION ♦ IRRADIATION ♦ LITHIUM 7 ♦ MEASURED VALUES ♦ METHYL RADICALS ♦ MOLECULES ♦ NEUTRON BEAMS ♦ NUCLEAR REACTIONS ♦ NUMERICALS ♦ PARTICLE TRACKS ♦ PARTICLES ♦ POLYESTERS ♦ POLYMERIZATION ♦ POLYMERS ♦ POLYVINYLS ♦ RADIATION CHEMISTRY ♦ RADIATION DOSES ♦ RADIATION EFFECTS ♦ RADIATIONS ♦ REACTION KINETICS ♦ STYRENE ♦ TRANSPORT THEORY ♦ VARIATIONS ♦ VINYL RADICALS ♦ WEIGHT
Abstract The radiation-induced polymerization of styrene, methyl methacrylate, and vinyl acetate containing small amounts of triethyl borate was studied. At the same absorbed dose rate, the rate of polymerization by the high LET particles from the reaction B<sup>10</sup>(n,α)Li<sup>7</sup> was found to be much lower than by γ-rays, while the average molecular weight of the polymer formed was higher. The results are explained by assuming that only free radicals in the tracks of fast δ-electrons are able to initiate long-chain polymerization. The fraction f of the energy of the heavy particles that is effective in producing polymerization amounts to 0.l6 for styrene, 0.09 for methyl methacrylate, and 0.04 for vinyl acetate (if f is made equal to unity in the case of γ-rays). It is shown that f decreases with increasing radiation sensitivity (G(R) value) of a monomer. Finally, the minimum kinetic energy of the δ-electrons that participate in the initiation of long-chain polymerization is calculated to be 170-240 ev, depending on the nature of the monomer.
ISSN 00223654
Educational Use Research
Learning Resource Type Article
Publisher Date 1964-02-01
Publisher Department Hahn-Meitner-Institut fur Kernforschung, Berlin
Journal Journal of Physical Chemistry
Volume Number 68
Issue Number 2
Organization Hahn-Meitner-Institut fur Kernforschung, Berlin


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