1996 Fiscal Year Final Research Report Summary
THE FACTORS CONTROLLING THE X-RAY INDUCED SOLID-STATE POLYMERIZATION-REACTIONS
| Project/Area Number |
06453013
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | HOKKAIDO UNIVERSITY (1995-1996)
Hokkaido University of Education (1994) |
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Principal Investigator |
OGASAWARA Masaaki Hokkaido Univ., Center for Res.Dev.Higher Educ., Pro., 高等教育機能開発総合センター, 教授 (60001343)
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| Co-Investigator(Kenkyū-buntansha) |
TAKENAKA Yasuyuki Hokkaido Univ.of Educ., Assoc.Pro., 教育学部, 助教授 (60251609)
KOIZUMI Hitoshi Hokkaido Univ., Fac.of Eng., Assistant, 工学部, 助手 (00175324)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Ionizing Radiation / Single Crystal / Solid-State Reaction / Polymerization / Topological Reaction / Polymer |
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| Research Abstract |
The purpose of this project is to clarify the factors controlling the polymerization reactions induced by photon and ionizing radiation in crystals.
1. We mainly studied 2+2 cycloaddition reaction in crystalline 2,5-distyrylpyrazine which had been known as typical topochemical reaction. From the pico-second laser-photolysis measurements, we found that excimer sites, probably originated from irregularity of the crystal lattice, playd an important role in the reaction. From the observation by pulse radiolysis that the similar excimers were formed by the irradiation of electron pulse, we expected the similar reaction to be occurred by ionizing radiation ; actually, it was confirmed by using ^<60>Co gamma-ray. Thus, we succeeded in initiating the polymerization reaction more homogeneously, in comparison with the case of photo-illuminated systems, by irradiating crystal throughout the bulk. This last part of the results was summarized in the paper submitted to Bulletin of the Chemical Society of Japan on March 13,1997.
2.We studied the isomerization reaction of radicals produced by ionizing radiation in two different model compounds of solid polyethylene, crystalline n-C_8H_<18> and c-C_<13>H_<28>, by using ESR.It was found that in the triclinic and the orthorhombic crystals the initially formed primary radicals were thermally converted to the penultimate alkyl radicals. Thus, one of the important factors which control the crosslinking reaction taking place in crystalline part of solid polyethylene was elucidated.
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