The following experiments were carried out in order to clarify the reason of the excellent wood bonding performance of AA PVA when used as an adhesive. The surface activity performance of AA PVA was evaluated, and the relationship between the pMDI dispersion property in the PVA aqueous solution and the ability to consume isocyanate (NCO) groups was examined in comparison with ordinary PVA, which was used with varying degrees of polymerization and varying quantities and distribution of hydrophobic groups introduced into the side chain. By the measurement of the surface tension of various PVA aqueous solutions and the interfacial tension between the various PVA aqueous solutions and n-hexane, it was found that the AA PVA aqueous solution has low surface tension and low interfacial tension with n-hexane. By testing pMDI dispersion in the various PVA aqueous solutions, the AA PVA aqueous solution was found to have high oil component dispersion performance and to have the ability to disperse the oil component in aqueous solution into smaller particles than ordinary PVA does. AA PVA also demonstrated rapid consumption of NCO groups in the PVA aqueous solution. From the above mentioned, the AA group was found to have excellent interface activity, not only as a hydrophobic group, but also as a functional group, with reactivity that disperses the oil component into aqueous solution.

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The aim of this study is to design dismantlable structural epoxy adhesives with heat-resistant adhesive properties. Epoxy resin formulations using glycidyl phthalimide (GPI) with high polarity of imide structure as a mono-functional epoxy possessed relatively high Tg and reduced rubbery modulus of the resin at temperature over Tg, compared to the case using other mono-functionalepoxies. Curing agents also had an important role on the heat softening behavior. The combination of dicyandiamide/dichlorophenyldimethylurea as the curing agents showed good balance on high Tg and softening over Tg. These findings led to the cured resin composition including 25% of GPI, which possessed Tg over 80℃, modulus over 3GPa at glass state, and rubbery modulus lower than 2MPa. Consequently, the combination of the resin formulation with GPI and 10% of expandable graphite enabled both good dismantlability over 200℃ by thermal expansion of the graphite and high shear adhesive strength of over 20MPa at 80℃.

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Cellulose acetate (CA; DS (degree of substitution)=2.45) films containing triphenylsulfoniumsalt, which is a typical photoacid generator, were prepared and their degradative behaviour by photoirradiation was examined. Decrease in molecular weight of CA and generation of acetic acid from the CA films were observed by the irradiation of xenon arc lamp light, which passed through a filter that absorbs light whose wavelength is shorter than 275 nm. As the triphenylsulfonium salt concentration increased, the decrease in molecular weight of CA and the generation of acetic acid from the CA films got increased. These results indicate that the acid generated from triphenylsulfonium salt acts as a catalyst and leads to main chain cleavage and deacetylation of CA by hydrolysis.

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