Influences of peeling rate and temperature on peeling behavior of polyacrylic block copolymer were investigated. For this purpose, poly(methyl methacrylatc)-block-poly(n-butyl acrylate)-block-poly (methyl methacrylate) triblock copolymer (MAM) with hard block contents of 23 (MAM-23) and 16wt% (MAM-16) and 1/1 blend with diblock copolymer consisting of same components(MA) (MAM-23/MA, total hard block content of 15 wt%) were used. The peeling process at the probe/ adhesive interface during the probe tack test was observed using a high-speed microscope at 23℃ with probe rate of 10 mm/s. Three different peeling mechanisms were observed. TypeA: Peeling progressed linearly from the edge to the center of the probe without cavitation (MAM-23). TypeB: Peeling progrossed linearly from the edge to the center of the probe with cavitation (MAM-16). TypeC: Cavitation occurred in the entire adhesive layer, and peeling initiation was delayed (MAM-23/MA). The peeling behavior of MAM-23 changed from Type A to Type B with a decrease of peeling rate (1mm/s) or temperature rising (40℃). There was no change for MAM-16 and MAM-23/MA. Although MAM-16 and MAM-23/MA have similar hard block content, their peeling mechanisms differed greatly. The greater flexibility of the soft blockck chain in the diblock copolymer resulted in improved the interfacial adhesion.

The strength evaluation of adhesively bonded joint with epoxy resin isinvestigated experimentally, in order to clarify the effect of surface roughness on the adhesive joints strength. In the present paper, adherends of single lap joint are consisted with aluminum alloy A2017 and stainless steel SUS304. Adhering surfaces roughness on the adherend metals are subjected to shot blast working by using glass beads under high air pressure. Evaluation of surfaces roughness on the adhering surfaces are applied ISO 25178-2:2012(E). Adhering surfaces roughness are changed by value of arithmetical mean height of the scale limited surface (Sa) under fixed numerical values of the other parameter of surface roughness as skewness (Ssk), kurtosis (Sku) and material ratios (Smr1 and Smr2) of three-dimensional surface texture parameters. The effects of surface roughness on the strength of adhesive joints are extremely small among the joints above preparing adherends. Furthermore, the influence on the joints strength by difference materials was showed Stainless steel joints are high strength property compared with aluminum alloy joints.