The influence of phase morphology of natural rubber (NR) and epoxidized natural rubber (ENR) blends on the properties of the blends was investigated, and the morphology of the blends was analyzed by dynamic mechanical analysis and electron micrographs. The results of dynamic mechanical analysis and electron micrographs indicate that NR/ENR blends in various compositions have multiphase structures, and that conversion of the co-continuous phase occurs at volume fraction of ENR near 0.35. Gas permeability and oil resistance of the blends were influenced strongly by the phase structure, and mechanical properties of the blends also corresponded to the phase conversion.

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The crystallization and the melting of vulcanized isoprene rubber under uniaxial deformation have been studied by the measurements of the stress, strain-temperature relation. The melting temperature increases approximately linearly with nominal stress for the rubbers crystallized at a fixed temperature and stress condition. It has been shown that the main origin of the rise in melting temperature with stress is the work of contraction upon melting rather than the entropy reduction on deformation in the molten state. The crystallization rate monotonically increases with nominal stress above the melting stress at a given temperature, while it shows a maximum against temperature at a given stress. The relation between the temperature and the nominal stress at the onset of crystallization is satisfactorily reproduced by the simplified kinetic model.

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Here, we have summarized the researches published in the field of carbon black reinforcement of elastomers over 30 years from 1950s to 1980s, including models, ideas and theories for the reinforcement. In particular, it is focused on the following questions, most essential and important from the view points of dynamic mechanics and mechanism of the reinforcement.
(1)Why is it possible to estimate the modulus increase of coarse carbon-filled rubber with the Guth equation, when it gives a value well below that of fine carbon-filled rubbers?
(2)Why does the stress increase in carbon-filled rubber as extension increases?
(3)Why does the tensile strength of carbon-filled rubber become ten times larger than that of unfilled rubber?
(4)Why does the addition of carbon black dissipate so much energy under cyclic deformation(Mullins Effect)?
Although the information thus summarized could answer only a part of the above questions, it could not give any total and systematic answer with a clear concept.

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Stringiness phenomena of PSA tapes at peeling were observed.
(1) Effects of the backing materials;
It becomes clear that the stringiness conformation of adhesives of the porous backings was observed as a honeycomb structure and that of the nonporous backing was a sawtooth shape structure.
(2) Effects of the peel load;
Stringiness phenomena of acrylic adhesive were observed under constant load conditions. In the results, peeling behavior was classified into the following two regions depending on peel load.
A) Balanced region of peeling load vs. stress distribution caused by deformation of the adhesive tape at considerably low peeling speed.
B) Unbalanced region where peeling occurred before peeling stress had been distributed equally in the adhesive at higher peeling speed.

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The cleaved mica plate was treated with various silane coupling agent, and the topography of the silane-layer on the surface was observed using an atomic force microscopy. For this purpose, the silanes having aminopropyl or methacryloxypropyl group as an organofunctional group with di- or trialkoxy group were used. The reaction medium (2-propanol or 2-propanol/water mixture), the concentration of silane and pH at the silane solution were varied, and the relation between the topography of the silane layer and the treatment condition was investigated. It was clarified that the topography was strongly affected by the above factors, and the smooth silane layer can be obtained by controlling of them.

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