NIPPON GOMU KYOKAISHI

Characterization of Adhesion Interlayer between Rubber and Brass by a Novel Method of Sample Preparation, Part. 1.

Analysis of Adhesion Interlayer by Exposing Reaction Layer Using the Filter

Takeshi HOTAKA, Yasuhiro ISHIKAWA, Kunio MORI

2004 Volume 77 Issue 3 Pages 79-84
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.79

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Instrumental characterization of an adhesion interface in a rubber-brass system often faces a difficulty in exposing the clean surface due to the stick of the rubber residue on the brass surface. We have succeeded in isolating the interface from the rubber matrix by inserting a filter paper between rubber and brass during the vulcanization. Clean interface was obtained by removing the filter paper after the vulcanization, enabling the detailed characterization of the interface by XPS from a practical rubber formulation.
Formulation of cobalt naphthenate did not contribute to the formation of adhesion interlayer in an initial stage of cure, but greatly affected the composition of copper sulfide during the vulcanization. It was found that the dose of cobalt improved the nature of interface at aging.
It was revealed that excess growth of copper sulfide was a main feature in the humidity aging, while the growth of zinc oxide was eminent in the hot water aging. Scheme of the aging reaction that depends on the interaction between the brass and external factors such as heat, water, and oxygen was considered.
In conclusion, the XPS analysis using the specific sample preparation shown in this study was found to be a powerful technique to characterize the adhesion Interlayer in not only model systems but also practical rubber formulation systems.

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Current Status and Prospect of Miniature Fuel Cells for Portable Devices

Minoru UMEDA, Isamu UCHIDA

2004 Volume 77 Issue 3 Pages 85-89
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.85

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Current status and prospect of miniature and small fuel cells for portable devices have been reviewed from the following viewpoints. (i) Key technologies for downsizing: two technologies of solid polymer electrolyte and direct methanol fueling promoted downsizing of fuel cells. Principles of the two technologies were also explained. (ii) Cell efficiency and methanol crossover: power generation efficiency was discussed based on a theoretical equation and in terms of overpotential. Especially, methanol crossover through the electrolyte membrane affects the overpotential. The mechanism was interpreted according to electrode reactions occurred at cathode. (iii) Anode reaction and electrocatalysts: methanol oxidation reaction was described with a major focus on a bifunctional mechanism. In addition, anode materials to accelerate the methanol oxidation were introduced. (iv) Cathode reaction and electrocatalysts: electroactive materials for oxygen reduction were presented. Moreover, cathode materials which exhibit tolerance for the methanol crossover were exhibited. (v) Development of electrolyte materials: surface modification and new com-partment construction of membranes were introduced in order to protect the methanol crossover. (vi) Fuel cell system: an extreme system of fueling and cathode exhaust recycling technology to enhance the cell efficiency and diminish the total size was demonstrated.

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Technical Problems and Future Perspective on Fuel Cells

Takuya Homma

2004 Volume 77 Issue 3 Pages 90-95
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.90

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At present, PEFC (Polymer Electrolyte Fuel Cell) is becoming more and more attractive on expectation of being especially realized as fuel cell propulsion system for electric vehicles and residential co-generation devices. Some car companies provided the governmental organizations with totally 5 fuel cell vehicles on a lease of 30 months on December 2 2002. These companies are planning to expand their marketing efforts for sectors including local public and private industrial organizations in 2003. With respect to phosphoric acid fuel cells, it is believed that these have already reached at the stage of practical applications as stationary co-generation power plants, though not yet being cost effective. SOFC as well as MCFC are attractive for especially electric utility because of its capability of realizing very high efficient power generation system. Several electric companies are developing various types of both planar and tubular SOFC cells. In order to improve the performance of mobile devices such as note type personal computers and mobile phone, especially in terms of power sources, many companies recently pay an attention to micro fuel cells.

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Current State and Future Prospects of Industrial On-Site Fuel Cell Systems

Tetsuo TAKE

2004 Volume 77 Issue 3 Pages 96-102
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.96

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The current state, problems for practical use, and future prospects of industrial on-site fuel cell systems based on fuel cells of the several hundred kilo-watt class such as phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), and solid oxide fuel cells (SOFCs) are summarized. A 200kW multi-fuel-type PAFC system, 250kW MCFC co-generation system, 300-kW-class MCFC-micro-gas-turbine hybrid system, 100-kW-class SOFC co-generation system, and 220kW SOFC-micro-gas-turbine hybrid system are investigated as examples of industrial one-site fuel cell systems. High efficiency in power generation and reductions of system and running costs are important prerequisites for the widespread use of industrial on-site fuel cell systems. The technology of PAFCs is already mature. However, their application is restricted by high system costs and low efficiency in power generation. Systems which are expected to find application in food factories, hotels, sewerage sites, and chemical factories are those that run on free fuel, such as biogas, digester gas, exhaust fuel (i.e. exhaust methanol), and byproduct hydrogen. Systems based on MCFCs and SOFCs are currently under development. They will enter widespread use in factories and other buildings in the near future because of their high efficiency in power generation.

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Carbon Black Reinforcement of Rubbers

Part3. Recent Progress in the Researches of the Carbon Reinforcement

Yoshihide FUKAHORI

2004 Volume 77 Issue 3 Pages 103-108
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.103

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In the last report, we summarized the researches published from 1950s to 1980s, concerning phenomena, theories and models in the fields of carbon black reinforcement of rubbers. In this report, we would like to extract some more works from the reports published during these 20 years periods. Although these reports do not directly address the reinforcement of carbon black for rubbers, they are quite important, indeed essential, for understanding the mechanism and mechanics of the reinforcement.
This presentation includes such results as, the stress analysis of rigid particle-filled system with large deformation FEM and the molecular slippage at the interface of carbon particle and matrix rubber at large extension and high temperature, and more over the volume expansion and the micro voids formation between adjacent carbon particles in the fine carbon black-filled rubbers under extension.

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[title in Japanese]

[in Japanese]

2004 Volume 77 Issue 3 Pages 109-115
Published: 2004
Released on J-STAGE: May 28, 2007

DOIhttps://doi.org/10.2324/gomu.77.109

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