Adhesives for protecting offshore structures from corrosion must not be degraded due to water absorption. They also should be soft enough to reduce the shock and less sensitive to interfacial crack propagation between steel and the adhesive. In this research, three polyurethane adhesives were examined by dynamic mechanical tests and they also examined by IR spectroscopy before and after the water immersion. Water diffusion through the interface/interphase was also measured. The IR spectroscopy results proved no chemical reaction occurring due to immersion into water. The experimental results also confirmed that the glass transition temperatures of polyurethane adhesives synthesized from polyors made from castor oil had a strong correlation with the coefficients of water diffusion as well as the saturation ratio. The glass transition temperature could be an important indicator to estimate the water penetration into the interface/interphase between titanium adherend and polyurethane adhesives.

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Poly (methyl methacrylate) / poly (vinyl alcohol) blend prepared by melt kneading is incompatible system. Two loss modulus peaks based on the components appear by a measurement of dynamic viscoelastic properties. It was found that the peak based on poly (methyl methacrylate) of this blend appeared at higher temperature than the peak of poly (methyl methacrylate) alone. This is expected to be caused by the specific interaction between components. Effect of saponification degree of poly (vinyl alcohol) in the range from 38 to 98mol% on the peak temperature was investigated. As a result, the peak temperature of the blend was elevated with an increase in the saponification degree of poly (vinyl alcohol). In the case of poly (vinyl alcohol) with saponification degree below 88mol%, μm order domains were observed by a scanning electron microscopic observation. Whereas, in the case of poly (vinyl alcohol) with saponification degree of 98mol%, no clear domain was observed, in spite of the poor moldability by the formation of strong specific interaction between components. Fourier transform infrared spectroscopic analysis showed the hydrogen bonding between a carbonyl group in poly (methyl methacrylate) and a hydroxyl group in poly (vinyl alcohol).

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Oriental lacquer has been generally used as adhesive and coating material. Further, it has been believed that oriental lacquer has antimicrobial activity, though this property has not yet been completely proved. In this paper, Antimicrobial activity was examined using E.coli for oriental lacquer film, some plastics and 22 kinds of woods in relation to lacquer wares. Antimicrobial activity was confirmed in oriental lacquer film, phenol resin and sun trees. Some compounds or polymers having phenol type hydroxy group are contained in these materials. We concluded that antimicrobial activity is due to this type of hydroxy group.

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