Journal of Materials Life Society
Online ISSN : 2185-7016
Print ISSN : 1346-0633
ISSN-L : 1346-0633
Volume 21 , Issue 1
Showing 1-9 articles out of 9 articles from the selected issue
Short Reviews
Original Papers
  • Hiroaki KOUZAI, Tomoyuki MATSUZAKA, Junichi KAMEDA
    2009 Volume 21 Issue 1 Pages 20-25
    Published: February 28, 2009
    Released: May 08, 2021
    JOURNALS FREE ACCESS

    It was investigated that photodegradation of dienepolymer in solution system by influence of Nitrosensitizer. Sensitizer was Naphthalene without Nitro again as a comparison by 1-Nitronaphthalene where luminescence was shown by ultraviolet rays in it and 1,5-Dinitronaphthalene was used and under violet irradiation by a mercury lamp. The reaction progressed easily by adding Nitrosensitizer, and IR became various in a short time on organic solvents with a meltable low molecular weight fall. Then, It was investigated the decrease in the dienepolymer molecular weight, along FT-IR and NMR of the irradiated polymers.

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  • Junichi KAMEDA, Hiroaki KOUZAI
    2009 Volume 21 Issue 1 Pages 26-32
    Published: February 28, 2009
    Released: May 08, 2021
    JOURNALS FREE ACCESS

    It was investigated that photodegradation of vulcanized rubber in solid-liquid phase in the presence of sensitizer. Shredded vulcanized rubbers were dipped in a small quantity of solvent, with addition of a sensitizer, and ultraviolet irradiation was applied for 72h. Significant decreases in the molecular weights of vulcanized IR and NR were confirmed. In particular, anthraquinone reduced the sample molecular weight to around 2,000. This reduction was ascribed to the small amount of energy required for first excitation of the polycyclic aromatic quinone, which allowed this substance to easily change into an active species. Degradation product had highly enhanced solubility, being soluble in alcohol, ketone, and many other organic solvents. From the structure analysis results of the degradation product, it is suggested that the reaction that reduced the molecular weight is ascribable to auto-oxidation reaction.

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  • Yasuhiro MIYAHARA, Kohshiroh MIZUNO, Tomoyuki ISHIKAWA, Kunihiko TAKED ...
    2009 Volume 21 Issue 1 Pages 33-39
    Published: February 28, 2009
    Released: May 08, 2021
    JOURNALS FREE ACCESS

    “Yuton” is one of Japanese traditional goods and it has been used as a elegant and excellent carpet during summer season because men and children feel comfortable in a Japanese room in which the “Yuton” is spreaded all over the room even at very hot summer day. This article is the result of the analysis on it that obtained by modern instrumental analysis, such as SEM, heat conduction measurement and infrared thermography. The “Yuton” is made by accumulating Japanese paper (“Washi”). The surface was dense and smooth. The coarse and the entangled structure of the fiber was observed in the lower part which contacts Japanese “Tatami” directly. The heat conduction value was 0.11W・m−1・K−1 and it was lower than other materials such as alminium, glass and acrylic plates. The results were reasonable because the “Yuton” is made by paper and the structure is that of typical keeping warmth materials. However, the heat scattering rate of various materials placing the palm of the hand on the infrared thermography were measured and the rate of the “Yuton” was smaller than the aluminium plate but larger than the glass and acrylic plates. The oil and water mixture from the palm was considered to move into from the smooth surface into the inner entangled site and evaporate from the surface of the fine fibers to remove the heat from the “Yuton”.

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  • Kensuke MIYAZAKI, Kyosuke MORIYA, Noriyasu OKAZAKI, Minoru TERANO, His ...
    2009 Volume 21 Issue 1 Pages 40-47
    Published: February 28, 2009
    Released: May 08, 2021
    JOURNALS FREE ACCESS

    The oxidatively degraded polypropylene (DgPP) was studied as a dispersing agent for fibrous cellulose (FC)/ polypropylene (PP) composite. The adequate preparation time of thermal oxidative degradation for DgPP was found to be 18 hour at 130°C. The DgPP contained functional groups composed of γ-lactone group and carboxylic acid groups. The addition of the DgPP presented the transparency improvement of FC/PP composite. This be-havior was originated from the grafted DgPP, which was produced by the esterification reaction between the OH group of FC surface and the γ-lactone part and carboxylic acid parts in DgPP. Observation of the scanning electron microscope (SEM) showed that the grafted DgPP coated the FC surface and improved adhesion property between the interface of the FC and the PP. The addition of 1mol% of DgPP brought about the improvement of FC/PP composite mechanical properties. These results demonstrated that the DgPP effectively acted as the dis-persing agent.

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