Laboratory test condition to predict tire tread wear was discussed, using the FPS wear test equipment manufactured by Ueshima Seisakusho Co. Ltd. Sample load was determined based on the sample dynamic footprint and inflation pressure of different tire groups. Most tire groups evaluate wear rate by volume loss per distance with the exception of giant mining tires which evaluate volume loss per hours. In light of truck, bus and passenger tires, the laboratory test in the present paper employed the volume loss per distance. In such case, slip ratio correlated with wear rate better than slip speed. The surface of the worn sample and wear debris indicated that the laboratory wear mechanism was identical to road wear mechanism which was considered plastic wear (P-wear) instead of the conventional elastic wear (E-wear).

Polarizing observation was carried out for nylon 12 (Ny12) films with a notch of ca. 0.2 mm length during uniaxial elongation. As the result, a ductile deformation behavior was detected, and a X-shaped area with higher retardation was observed around the notch extending to 45˚inclined direction to the uniaxial elongation direction. Moreover, during the uniaxial elongation, in-situ wide angled X-ray diffraction (WAXD) measurement were performed at various positions in the Ny12 film specimens. As a result, a crystal phase transition from γ-crystal to α-crystal seemed to occur in the region where higher retardations were observed. Since the intrinsic birefringence in α-crystal is higher than those in γ-crystal and amorphous phases, the increase in retardation can be caused by increase of α-crystalline fraction.

Currently, chemical substances and pesticides are evaluated and managed by various laws and regulations in Japan. However, there are some problems from the viewpoint of impact on the ecosystems. Tetramethylammonium hy droxide (TMAH), which is mainly used in the manufacturing process of semiconductors and liquid-crystal panels, is not subject to effluent regulation under the Water Pollution Control Law. Reproduction test with Ceriodaphnia dubia indicates a high sensitivity of this species to TMAH. Therefore, TMAH concentration in wastewater discharged should be managed toward the protection of aquatic organisms. Carbendazim is the hydrolysate of benomyl and thiophanate-methyl, which are the active ingredients of pesticides, in the environment. Carbendazim has been detected in environmental water and sediment in Japan, but degradation products are not considered in pesticide registration system in Japan. We conducted sediment-water toxicity test of carbendazim with Chironomus yoshimatsui, and toxicity value was obtained. It is necessary to consider the toxicity value of carbendazim when evaluating the toxicities of benomyl and thiophanate-methyl in sediment in the future. Governments, companies and researchers need to continue to address these issues of chemicals that affect ecosystems.

In this paper, we introduce the basics of pressure-sensitive adhesives (types of adhesives, test methods for adhesive properties, and the mechanism of adhesion), and use rubber-based adhesives containing various additives as an example to explain the mechanism of durability (deterioration). Next, we explain that the research on changes in adhesive properties over time, focusing on the efforts of “time-dependent mechanism of adhesive properties and life prediction" conducted by the four industry-academia collaborative research groups of the Adhesive Research Group.

Many polymer scientists have devoted to study on the synthesis and property of cyclic polymers which have no terminal end, being much different from most common polymers. In this review, we discuss mainly on the synthesis of cyclic polymers by utilizing the rotaxane’s structural characteristics, “the rotaxane method”. For it, the macromolecular rotaxane switch which can play an important role to control the polymer topology, i.e. linear or cyclic, has been synthesized to regulate the relative position of the components of macromolecular rotaxanes. Addition of [1]rotaxane moiety to polymer terminal gave [1]polyrotaxane of which crown ether wheel component was moved from one to another site by breaking the attractive interaction with the ammonium site to eventually afford “cyclic polymer". The solution property between linear and cyclic polymers obtained was compared to evaluate the effect of cyclic topology: cyclic polymer showed smaller hydrodynamic radii than the linear counterpart. Cyclic block copolymer having poly(ε-caprolactone)-b-(δ-hexanolactone)was also prepared via the living ring-opening polymerization followed by the terminal end-cap and the control of the attractive interaction. The cyclic topology was characterized by the difference in crystallinity and glass transition temperature in comparison with the linear one. Additional syntheses of cyclic polymers by different rotaxane methods will be discussed in the next chance.

In the mold vulcanization molding process, the unvulcanized rubber compound is filled into the sealed mold and under high pressure and temperature, it is transformed from the unvulcanized state into vulcanized rubber. The unvulcanized rubber compound is subjected to shear forces and associated thermal history during the processing process prior to vulcanization, which greatly affects its flowability and vulcanization behavior in the mold. In order to manufacture rubber products with excellent properties and functions, the flow behavior of the unvulcanized rubber compound in the mold must be analyzed and reflected in the compound composition of the rubber compound, rubber mold design, and vulcanization conditions. For this purpose, analysis of the flowability in the mold, pressure behavior, and visualization methods have been studied, but the behavior has not yet been clarified. In addition, improvement of flowability by compounding design is also being studied.

A synchrotron radiation experiment and a large-scale simulation are indispensable for development new functional rubber materials in recent years. In this series of lectures, I will try to explain about an analysis of structure of filled rubber vulcanizates by cooperation of a synchrotron radiation experiment and a large-scale simulation. In this first article, I will discuss an ultra-small angle X-ray scattering experiment of end-modified styrene butadiene rubber, and a reorganization of filler structure by large- scale reverse Monte Carlo simulation using this experimental data.