NIPPON GOMU KYOKAISHI
Print ISSN : 0029-022X
Volume 80, Issue 9
Displaying 1-7 of 7 articles from this issue
  • Tsutomu SHIOYAMA, Kunio MORI, Yoshiyuki OISHI, Hidetoshi HIRAHARA, Eii ...
    2007 Volume 80 Issue 9 Pages 325-330
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    The adhesion stability of rubber/galvanized-steel direct bonding system was studied under several environmental conditions. Following results were obtained. (1) Aging between plates of press machine heated with steam accelerates the degradation of adhesion about 10 times compared with that in oven at the same temperature. (2) Aging under relative humidity 95% or hot water immersion accelerates about 18 times compared with press machine plates aging at the same temperature. (3) Neither ozone aging nor weather meter degradation accelerates so much as high humidity or hot water immersion. (4) The depth of rubber deterioration was 8mm by high pressure oxygen test, 3-4mm by high humidity test or hot water immersion test, and 2mm by hot oven test. (5) The activation energy calculated from the data obtained by press machine plate aging was 107kJ/mol.
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  • Nobuaki OMATA
    2007 Volume 80 Issue 9 Pages 331-337
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    It is well-known that there is a close relationship between the friction of the tire and the viscoelasticity of the tread rubber, especially loss tangent tan δ in the high friction frequency band (102-106Hz). But it has not been verified under the real frequency and temperature conditions. In this respect, the ultrasonic (high frequency) viscoelasticity measuring method using surface reflection wave was investigated recently.
    In this report, the relationship between friction coefficient and tan δ, measured by the ultrasonic viscoelasticity measuring method using surface reflection wave, is shown.
    Furthermore, the high frequency vibration is found to exist during slip of rubber on a rough glass plate.
    The ultrasonic viscoelasticity sensor for a tire is expected to be a tool for the quality lifecycle management and the safety of automotive vehicles.
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  • Mika SUZUKI, Tomoko WATANABE, Yoshito OHTAKE
    2007 Volume 80 Issue 9 Pages 338-343
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Use of rubber products and minerals containing higher than 0.1wt% asbestos was banned in 2006. For the regulation, there is a real need for accurate trace analysis of asbestos in rubber products and minerals. We reviewed the present analytical methods for asbestos and make some recommendations to avoid erroneous measurement. Firstly, proper pretreatment of rubber products is essentially important to exact analysis. Secondary, it is necessary to combine two or more analysis techniques such as XRD, SEM, PCM and DTG for qualitative or quantitative analysis of asbestos. XRD is the most powerful instrument that can be used detection and measurement of asbestos. Asbestos can be directly observed with SEM and PCM. Though DTG is useful for identification of serpentine minerals, it is necessary to pretreat the matrix dissolution to measure the concentration of asbestos.
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  • Hiroshi KOBAYASHI
    2007 Volume 80 Issue 9 Pages 344-349
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Industrial robots have been the driving force of the technological establishment of Japan, which has produced a wide variety of low-cost, high-quality products. In these days, because of an aging society where children are decreasing in number, robots are expected to be developed for supporting human daily life. However, few provide physical support or can directly provide human assistance. From these points of view, author focuses on developing the new robot technology for physically and directly supporting human movement in daily life. In this paper, a “muscle suit” for the upper body that will provide muscular support for the paralyzed or those otherwise unable to move unaided and a “active walker” by which a user can walk if he/she does not have any muscular power are introduced
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  • Hiroshi MORITA
    2007 Volume 80 Issue 9 Pages 350-355
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    We review our recent studies of rubber system using coarse-grained molecular dynamics (CGMD) simulation. The CGMD simulation is one of the powerful tools to clarify the molecular chain dynamics of the rubber material in the deformation process. In this review, we show two topics listed below; the stretching of the rubber material in which the cross-linker is included, and the chain dynamics near the filler. In the first topics, we observe the chain conformation in the stretching. In this process, we can obtain the one or two strong force line of bonds. This nature indicates that the deformation of the rubber takes place in non-affine process in the nano-scale. In the second topics, we study the molecular motion near the filler, so called in the bound rubber layer. We construct the two models; the grafting chain model and the adsorbed chain model. We observe the local mean square displacement and the local glass transition temperature. We can observe that the chain moves slowly near the filler due to the restriction of the grafting or due to the attractive interaction between filler and polymer.
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  • 3. Structural Control and Functionalization of Oligomeric Silsesquioxanes (Part 2)
    Yusuke KAWAKAMI
    2007 Volume 80 Issue 9 Pages 356-359
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Oligomeric silsesquioxanes show excellent properties derived from their unique structure, and have been used as component to improve the property of various polymeric systems. Reaction conditions to obtain specific structure of the silsesquioxanes are discussed paying attention to the reaction mechanism. Some functionalization reactions were also illustrated.
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  • 6. Creation of Functional Nano-materials Via Self-organization of Block Copolymers
    Kenji SUGIYAMA, Akira HIRAO
    2007 Volume 80 Issue 9 Pages 360-366
    Published: September 15, 2007
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    In general, each segment of block copolymer may possibly be phase-separated at molecular level, followed by self-organizing to form various molecular assemblies in bulk as well as solution. These assemblies are nano-sized, specially shaped, and three-dimensional well-ordered supra-structured materials with many potential applications and expected to be utilized as organic nano-devices in. the field of nanotechnology. This review describes recent advances on creation of nano-materials based on such molecular assemblies via self-organization of block copolymers. In order to practically use self-organized molecular assemblies, they are isolated as nano-materials by the fixation of objective domain, followed by removal of other domain in molecular assemblies. Furthermore, nano-materials are also created by utilizing other molecular assemblies as templates. For example, conductive poly (pyrrole) nano-wire could be obtained by the polymerization of pyrrole introduced into a nano-porous monolith template, followed by removal of this template with a selective solvent. Several designed nano-objects are also obtained by fixation of the micelles corresponding to molecular assemblies formed in selective solvents under selected conditions. All materials herein demonstrated are quite novel nano-sized materials with many characteristics mentioned above and are expected as essential candidates of organic nano-devices in the very near future.
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