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Free Volume and Cryogenic Properties of Hybrid Materials

  • T. Okada
  • S. Nishijima
  • S. Ueno
  • Y. Honda
  • K. Niihara
  • A. Nakahira
  • K. Kijima
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)

Abstract

Cryogenic characteristics of hybrid materials, which consist of epoxy and nanosize ceramic filler such as silica, have been studied in order to control the crosslinking density or the free volume size of polymeric materials. The positron annihilation lifetime (PAL), by which the free volume size of polymeric materials can be evaluated, was measured and the relationship between positron lifetime and cryogenic properties such as fracture toughness or thermal contraction, were investigated down to cryogenic temperatures. It was found that cryogenic properties of hybrid material depend on PAL and free volume size. As an attempt to understand the microscopic state, molecular dynamics simulations were carried out. It also suggested that molecular design of hybrid material was suitable to obtain better cryogenic properties.

Keywords

Fracture Toughness Molecular Dynamic Simulation Free Volume Hybrid Material Coupling Agent 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    K.Shibata, S. Nishijma, T.Okada, K.Matsumoto, M.Hamada and T.Horiuchi, Adv. Cryog. Eng. 29: 175 (1984).CrossRefGoogle Scholar
  2. 2.
    F.Sawa, S.Nishijima and T.Okada, Cryogenics 35: 767 (1995).CrossRefGoogle Scholar
  3. 3.
    A.Iwamoto, S.Nishijima and T.Okada, IEEE Trans. Appl. Supercond. 3: 269 (1993).CrossRefGoogle Scholar
  4. 4.
    S. Nishijima, K. Nojima, K. Asano, A. Nakahira, T. Okada and K. Niihara, Adv. Cryog. Eng. 40: 1051 (1994)Google Scholar
  5. 5.
    T.Saegusa and Y.Chujo, Macromol. Chem., Macromol. Symp., 64: 1 (1992).CrossRefGoogle Scholar
  6. 6.
    T.Okada, S.Nishijima, Y.Honda and Y.Kobayashi„ Suppl. J. Phys.Il. 3: 291 (1993).Google Scholar
  7. 7.
    S.Nishijima, T.Okada and Y.Honda„ Adv. Cryog. Eng. 40: 1137 (1994).Google Scholar
  8. 8.
    Q.Deng, C. S. Sundar and Y. C. Jean, J. Phys. Chem. 96: 492 (1988)Google Scholar
  9. 9.
    Y. C. Jean, “Positron and Positronium Chemistry” (Edited by Y. C. Jean), World Scientific, London, 1 (1990)Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • T. Okada
    • 1
  • S. Nishijima
    • 1
  • S. Ueno
    • 1
  • Y. Honda
    • 1
  • K. Niihara
    • 1
  • A. Nakahira
    • 2
  • K. Kijima
    • 2
  1. 1.ISIROsaka UniversityIbaraki Osaka 567Japan
  2. 2.GoshokaidochoKyoto Institute of TechnologyKyoto 606Japan

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