he reactivity of Si-OH group/Si-OH group, Si-OH group/Al-OH group and Si-OH group/Si-OEt group has been investigated by deriving the activation energies from the adhesion of cured silicone rubbers. Avrami equation is used ti derive the activation energies of curing reactions of epoxy resins and unsaturated polyesters. We thought that Avrami equation could be applied to adhesion process, because the generation of the interface bonding in adhesion could be consider as a kind of curing reaction. As a result, Arami plot was a linear function, and it was shown clearly that Avrami theory was effective. The activation energies of Si-OH group/Si-OH group, Si-OH/Al-OH group and Si-OH group/Si-OEt group were 90.7, 116.6 and 131.7kJ/mol, respectively. From the results, the activation energy clearly depends on the difference of reaction space and steric effects.

Polyurethane prepolymer is industrially important and useful resin. It is widely applied to curable resin composites such as adhesives, sealing materials, paints, and coating agents. However, detailed structure analysis of the resins is difficult, because its preparation is usually accompanied by various side reactions. In this study, we investigated polyether-based polyurethane prepolymers which were prepared from diols or triols with diisocyanate by size exclusion chromatography-infrared (SEC-IR) measurements. As a result, a characteristic molecular weight dependence of the IR spectrum was found in the polyurethane prepolymers. We expect that this technique may be a powerful tool to identify the chemical structures of various unknows polyurethane prepolymers.

The adhesive strength of single lap joint bonded with epoxy resin was investigated experimentally. The factor which effects on the adhesive strength was investigated experimentally under the condition that the surface roughness and the wettability of the adherend were approximately constant in the loading direction. Three kinds of metals aluminum alloy A2017, stainless steel SUS304 and mild steel SS400 were used for the experiment. Firstly, this report revealed that the adhesive strength of single lap joint was strongly influenced by the value of bending stiffness when the adhesive strengths were mostly the same. Moreover, the adhesive bonded length was determined when the compressive strength coincided with the adhesive strength. As a result, the synthetic strength diagram of single lap joint was proposed to use for the total evaluation of the adhesive joint strength.