In order to improve the fracture toughness of epoxy resin (Ep), three kinds of polyimides microparticles (PI) were incorporated with Ep.Material properties of the blends were estimated by flexural and fracture tests and WAXD (etc.) and the toughening mechanism was studied by SEM micrographs taken after the toughness tests.The mechanical properties of PI-A ("AURUM") /Ep depended on the mixture ratio of PI-A.And there were characteristic differences in the flexural properties and fracture toughness of three kinds of PI/Ep. Namely, the blend which is composed of PI with the lower crystallinity showed the higher value of flexural strength. And the blends which are composed of PI with the higter crystallinity showed the higher values of fracture toughness. These results indicated that the flexural properties and fracture toughness of PI/Ep had relations to the crystallinity. Also the fracture toughness of the PI/Ep depended on the feature of PI.

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Liquid crystalline epoxy resin with mesogenic group was synthesized and its adhesive bonding properties were compared with that of bisphenol-A type epoxy resin. Bonding strength of the former resin system showed higher value than that of the latter resin system. It was suggested that the high bonding strength of the liquid crystalline epoxy resin system was due to the large creep deformation of this resin system along the stress direction. Bonding strength of the cured systems has a maximum peak with the progress of curing, because of the increase in the internal stress occurred with the curing shirnkage of epoxy resins.

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The catalytic activity of H₂PtCl₆ in the hydrosilylation was evaluated in the presence of acetylene derivatives to clarify the relationship between the acetylene structures and their controllability of the hydrosilylation process. From the study on the hydrosilylation reaction of trimethylvinylsilane with triethylsilane at various temperatures, it was found that the catalytic activity was dependent upon the substituents (electronic and steric factor) on the added acetylene derivatives. In cases of diacetylenes, the catalytic activity was suppressed remarkably compared to the cases of monoacetylenes. The curing reaction of silicone resin was also carried out in the presence of acetylene derivatives to observe the same tendency to the model reaction.

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Infrared microspectroscopic spectra of wood-based materials including an isocyanate adhesive were recorded by diffuse reflectance method. We investigated the relationship between the NCO concentration and the absorbance of asymmetric stretching vibrational band (2270cm^-1) of the functional group in the MDF boards. Automation and refinement of the two-dimensional infrared measurements were carried out, and the distributions of residual NCO group were obtained in several kinds of MDF boards and plywood. Furthermore, with a view to visualizing the distributions, the maps of NCO group were displayed by the color corresponding to its concentration.

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