| Project/Area Number |
08651062
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子合成
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| Research Institution | High Energy Accelerator Research Organization |
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Principal Investigator |
SUZUKI Takenori High Energy Accelerator Research Organization, Radiation Science Center, Professor, 放射線科学センター, 教授 (40162961)
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| Co-Investigator(Kenkyū-buntansha) |
NUMAJIRI Masaharu High Energy Accelerator Research Organization, Radiation Science Center, 放射線科学センター, 助手 (20189385)
OKI Yuichi High Energy Accelerator Research Organization, Radiation Science Center, 放射線科学センター, 助手 (40204094)
MIURA Taichi High Energy Accelerator Research Organization, Radiation Science Center, Assista, 放射線科学センター, 助手 (80209717)
KONDO Kenjiro High Energy Accelerator Research Organization, Radiation Science Center, Profess, 放射線科学センター, 教授 (20004434)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Positron Annihilation / Thermosetting resin / Polymerization / Free Volume / Cyanate / Lifetime / Positronium / Epoxy resin |
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| Research Abstract |
Positron annihilation lifetime spectroscopy (PALS) has been applied successfully in solid state physics to detect defects and impurities. Recently, PALS has been applied to polymers. Positrons injected into polymers from radioisotopes such as ^<22>Na lose energy through interaction with atoms and molecules. After loosing the energy, positrons with a few hundred eV make the terminal spurs, which consist of ions, electrons and positrons, and then the positrons from hydrogen like atom, positronium (Ps). Ps diffuses in polymers until it is trapped in intermolecular spaces. Ps decays in these spaces and the size can be measured by the long lifetime (tau_3) of ortho-Ps.
In this research, polymerization of bisphenol A dicyanate was examined using PALS and the increase in the specific volume was observed with the increase in the degree of polymerization. Also free volumes of several epoxy resins have been studied. The shift of the size of free volumes was observed when a THPM epoxy resin absorbed water.
Also, the relaxation of polymer structures was discussed using PALS.After quenching the novolac epoxy resins to liquid nitrogen temperature, the large intermolecular spaces were observed, which would be formed by combining several small spaces due to the stress among polymer chains.
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