| Co-Investigator(Kenkyū-buntansha) |
OKI Yuichi Applied Research Laboratory, High Energy Accelerator Research Organization, Research Associate, 放射線科学センター, 助手 (40204094)
MIURA Taichi Applied Research Laboratory, High Energy Accelerator Research Organization, Research Associate, 放射線科学センター, 助手 (80209717)
KONDO Kenjiro Applied Research Laboratory, High Energy Accelerator Research Organization, Professor, 共通研究施設, 教授 (20004434)
NUMAJIRI Masaharu Applied Research Laboratory, High Energy Accelerator Research Organization, Research Associate, 放射線科学センター, 助手 (20189385)
|
|---|
| Research Abstract |
Relaxation behavior of polymers has been studied by the thermo mechanical method (TMA) and NMR. Recently positron annihilation lifetime spectroscopy (PALS) has been applied to study the relaxation behavior of polymers. PALS is utilizing the lifetime measurement of positronium (Ps), which is hydrogen like atom composed of positron and electron. From the lifetime of PS, the size of free volume can be deduced. The intensity of the long lived component related to the PS in the free volume can be a good measure to study many factors such as chemical structure, three dimensional structure, radicals, electronic structure, etc.
Hence from the intensity we can discuss characteristics of polymers, if we can prepare samples or experimental condition. We have observed the increase in the intensity at low temperature with the elapsed time. This can be explained by the fact that trapped electrons, which are induced by the radiation effect, increase with the elapsed time. The trapped electrons are kept in the potential created among polymer structures because of the freezing of the structure. Increasing the temperature of samples, the intensity gradually decreases and the after minimum, it starts increasing again. This decrease at low temperature is related to the relaxation behavior, which is originated from the movement of polymer structures.
|
