• Elastomers and Composites
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• v.25 no.3
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• pp.195-202
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• 1990

Rubber-modified polyurethane resin which was prepolymer type terminated with NCO, was synthesized by reacting isocyanate groups[NCO] and hydroxyl groups[OH]. Polybutadiene rubbers which had OH groups in the side of rubber chains, were charged at ratio $0%{\sim}40%$ of solid component in reactants. For products, physical properties were investigated experimentally. The results abtained in experiment were as follows. 1. Liquid resin and dried film was good solubility and clearity at less than 25%, 20% of rubber without being related to sort. 2. G-1000 showed better properties than R-45HT in solubility, dring time and adhesive strength. 3. Dring time and adhesive strength were considerably influenced by molecular weigh and structure of rubber. 4. In using 25% of mixed rubber(G-1000/R-45HT=50/50), It represented best properties in dring time(10 minute) and adhesive strength($23Kg/cm^2$).

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.53-60
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• 2004

Adhesive-bonded joints are widely used in the industry. Recently, applications of adhesive bonding joints have been increased extensively in automobile and aircraft industry. The strength of adhesive joints is influenced by the surface roughness, adhesive shape, stress distribution, and etc. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, as the fundamental research of adhesive bonding joints, the effects of adhesive shape and loading speed on bonding strength properties and durability of aluminum to polycarbonate single-lap joints were studied. To evaluate the effect of adhesive shape, several modified shapes were used, and loading speeds were varied from 0.05 to 5mm/min. As a result, the load distribution showed a brittle fracture tendency. The trigonal edged single lap and bevelled lap joints showed the higher strength than the plain single lap, trigonal single lap, joggle lap and double lap joints in same adhesive area. The fractures of trigonal single lap and trigonal edged single lap joints that had the higher strength level were shown as the mixture type of the cohesive and interfacial-failure, mostly joggle lap joints that had the lower strength level were shown as the adhesive-failure.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.840-847
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• 2003

The bonding of adhesive joints of adhesive joints is influenced by the surface roughness of the joining Parts. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, it is shown that surface treatment affects adhesive strength and durability of alumina/polycarbonate single-lap .joints, and leading speed affects tensile-shea strength of adhesive Joints. To evaluate effect of surface treatments on the adhesive strength, several surface treatment methods are used, that is, cleaning, grinding, SiC polishing and sand blasting. It is shown that an optimum value of the surface roughness exists with respect to the tensile-shea strength of adhesive joints. The adhesive strength shows linear relationship with the surface roughness and loading speed. And the mechanical removal of disturbing films of lubricants, impurities and oxides make adhesive strength increase significantly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.5
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• pp.474-481
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• 2009

Fracture models and criteria of adhesive with two parameters, namely $G_C$ and ${\sigma}_{max}$, have been developed to describe the fracture process of adhesive joints. Cohesive zone model(CZM) is a representative two parameter failure criteria approach. In CZM, ${\sigma}_{max}$ is a critical, limiting maximum value of the stress in the damage zone ahead of the crack and is assumed to have some physical significance in adhesive failure. Based on CZM and finite element analysis method, the relationship between fracture load and adhesive properties, as $G_{IC)$ and $({\sigma}_{max})_I$, was investigated in adhesively bonded joint tensile test and T-peel test. The two parameters in tensile mode loading were evaluated by using the relationship. The value of $G_{\IC}$ evaluated by proposed method showed close agreement with analytical solution for tapered double cantilever beam(TDCB) test which proposed in an ASTM standard.

• Composites Research
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• v.22 no.2
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• pp.14-17
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• 2009

Adhesive joints are widely used for structural joining applications in various fields and environmental conditions. Polyurethane adhesive is using for LNG carrier with cryogenic temperature condition. In industrial application of polyurethane adhesive, void of adhesive layer is often discussed regarding its effects on bonding properties. In present study, artificial void were prepared on Polyurethane adhesive layer with various size and location. The single lap shear test was carried out by using prepared specimens under $-170^{\circ}C$. As a result, it was confirm that the void of adhesive layer didn't affect the adhesion properties independent of their size and location.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.613-617
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• 1998

This study deals with the effect on adhesive strength properties of fiber sheet layer and maintenance position of coccrete structure reinforced using epoxy resin carbon and aramit fiber sheet. Properties of epoxy resin adhesive strength of the concrete bridge slab, tunnel and wall etc. reinforced using fiber sheet under many different environment change according to condition of concrete substrate, temperature, moisture, curing, cleaning, and chemical effects and so on. The purpose of this study is that it makes the estimation value of adhesive strength of concrete substrate and fiber sheet reinforcing layer penetrated epoxy resin under high temperature(9$0^{\circ}C$), chemical attack and condition of curing.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.1
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• pp.45-50
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• 2006

In order to analyse the properties of the fiber-adhesive that was used as Flocking process we synthesized quaterpolymer with the variation of the types of monomer ratio by emulsion polymerization. We characterized the properties of this adhesive: Differential Scanning Calorimeter(DSC), Thermogravimetry Analysis(TGA), Raman spectroscopy. The polymer was synthesized by changing the using amount of 2-EHAM, and then we investigated the characteristics of glass transition temperature(Tg), melting temperature(Tm), thermal stability and hydroxyl group respectively. The optimum monomer composition was 36.84% EAM, 15.79% MAM, 42.1% 2-EHAM and 5.26% AAc.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.133-134
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• 2006

In contrast to paints, the surface appearance of adhesive materials is of minor importance, because the adhesive is invisible between the two substrates. Therefore, the rheological properties needed to apply an adhesive dispersion by spray coating can be quite different. The influence of three different kinds of thickeners on the spraying behaviour of polyurethane adhesive dispersions was investigated. The associative thickener showed only minor changes, whereas the higher molecular weight soluble thickeners dramatically changed the spraying angle and the amount of overspray. Determination of the elongational viscosity by means of the CaBER rheometer proved to be of limited use for thickened dispersions.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.21-27
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• 2011

This study was carried out to examine properties of water resistant plywood by using serum protein adhesive which is natural, environment-friendly and human-friendly. For the preparation of the serum protein adhesive, pig blood from slaughterhouse was centrifuged and serum was separated from corpuscles and concentrated to 30% by dry weight basis. This concentrated serum protein was modified with PF resin (50% NVC) with the ratio of 9 : 2.5. Plywood made by this modified serum protein gave 1.21 N/$mm^2$ of dry bonding strength, 0.80 N/$mm^2$ of wet boil bonding strength, 0% of cyclic delamination test value, and 0.025 ppm of HCHO emission, which met the excellent super $E_0$ grade and water resistant plywood.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.560-567
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• 2010

This study was conducted to evaluate the in vivo gastrointestinal survival and adhesive properties of orally administered Lactobacillus brevis FSB-1. ELISA conducted using polyclonal antibodies specific for L. brevis FSB-1 was able to detect the organism in feces; therefore, we used ELISA to determine the concentration of lactic acid bacteria in feces collected from Wister rats that had been administered $10^{10}$ cells/rat/d orally for 20 d. The mean recovery of L. brevis FSB-1 was approximately $10^{7.22}$ cells/g of wet feces during the oral administration period, and $10^{7.50}$ and $10^{7.46}$ at 8 and 10 d after the end of oral administration, respectively. These results indicate that L. brevis FSB-1 was able to survive in the gastrointestinal tract of rats, and that it had a high adhesive property in rat colons.