The impact fatigue strength of anacrylic adhesive under impact tensile load tested when repeated impact loads were applied to tubular butt joints. The material of the adherend was aluminium alloy A5052-H34. Anacrylic adhesive was Hardloc M-372-20 As experimental equipment was developed for the impact fatiguetest. The shape of specimen is hollow cylindrical but joint. In the impact fatigue test, the thickness of the adhesive layer was 0.1mm. The experiment was conducted at room temperature(23±2℃). Times of repeated impact load decrease as an initial incident stress value was increase. The specimen didn't fracture when the incident stress was 9MPa even though it was subjected to repeated impact loads 1 million times.Fracture occurred over at 10MPa. Therefore, the fatigue limit is considered to be 9MPa.

The surface treatment of spherical silica particles using glycidoxy or amino functional silane coupling agent was conducted and the effect of the alkoxy group number on the molecular mobility of the silane chain with multilayer coverage was investigated by 1H pulse nuclear magnetic resonance.The silica particles were treated with 2-propanol solution and heated at 120℃ for 24h after solvent evaporation. For multilayer coverage, the linear chain and network structures were expected to form on the surface by polycondensation reaction using the di-and trialkoxy structures, respectively. However, the rigid network structure was formed from both the di-and trialkoxy structures for both glycidoxy and amino functional silanes. Fourier transform infrared spectroscopic analysis revealed that ring opening of the epoxy group occurred, followed by reaction to form the network structure, even with the dialkoxy structure for the glycidoxy functional. Ring opening of the epoxy group could be reduced by setting the heating temperature at 80℃, and the linear chain structure was formed by di-alkoxy structure. In the case of amino group, it was seemed to be caused by the formation of hydrogenbond between the aminogroup and the silanolgroup on silica surface.

Cured epoxy resin (Ep)/phenoxy resin containing carboxyl groups and phosphorus (COOH-P-Px) blends showed better flow properties with maintaining the good resistant reliability than those of cured Ep/phenoxy resin containing phosphorus (P-Px) blends and cured Ep/phenoxy resin containing carboxyl groups (COOH-Px) blends. That could be depending on rigid molecular structure of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) which is a resource of phosphorus and carboxyl groups which can react with epoxy groups. However, since the peel strength of cured Ep/COOH-P-Px blends showed was not improved well, we knew that as a problem we should solve from now on.