• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.14-14
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• 1996

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.461-469
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• 2010

Polyurethane adhesive is used in various fields as flexible packaging materials including a food packaging field. Therefore, the purpose of this study is synthesis of polyurethane adhesive which uses aliphatic isocyanate, and compares with aromatic isocyanate. The isocyanates for this test are toluene-2,4-diisocyanate(TDI), hexamethylene diisocyanate(HDI), 4,4-dicyclohexyl ethane diisocyanate($H_{12}MDI$), and isophorone diisocyanate(IPDI). And, the effect of any other diisocyanate are evaluated by several methods as for curing rate test, accelerate weathering test, and peel strength test. The polyurethane adhesive using curing catalyst and HDI has adhesion strength of about 560 g/15 mm between aluminium foil and nylon, about 1,520 g/15 mm between nylon and CPP. Those parameters are similar to polyurethane adhesive with TDI. Also, in case of curing rate, those are similar to TDI type polyurethane adhesive. Moreover, data of ${\Delta}E$ as color variation by QUV tester is equal to 4.12, as 48% against those of TDI type.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.102-111
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• 1998

This study was concerned with the development of a heavy duty rust-converting agent, the function of which is to form metal complex coatings, containing vinyl halide-acrylic terpolymer emulsion, defoamer, emulsifying agent, glass flakes, chelating agent such as gallotannic acid, gallic acid, and pyrogallic acid, and other additives. The resulted emulsion products(Sample No.1~No.5) were characterized through test either in the forms of emulsions, which include Viscosity, Penetration rate, Acidity and Film drying rate test, or in the forms of coated layer on rusty steel substrates by FT-IR, which include hardness, gloss, salt spray, adhesion and flame retardant test. The test results are as follows ; Penetration rate(0.1~0.4 mm/min), Solid content(70%), Acidity (pH 1.8~2.0), Specific gravity(1.30~1.35), Film drying rate(108min, RH 40% ; 150min, RH 80%), Gloss(83~92, incident angle $60^{\circ}$; 88~97, incident angle $85^{\circ}$), Pencil hardness(4H~5H), Adhesion (100/100), Salt spray test(>720Hr), LOI(%) value(38%), Vertical burning test(UL 94-v-l). According to the various performance of specimens show above, the evaluation of the availability of this heavy duty rust-converting agent can be concluded that all the samples(No.1~No.5) are capable of being used in the field of chemical plant and in the hazard areas of fire and explosion potential. It was observed that the properties of sample No.2, especially gloss and hardness, were much better than that of the other samples.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.11-18
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• 2011

The quantitative interfacial adhesion energy of the Cu-Cu direct bonding layers was evaluated in terms of the bonding temperature and Ar+$H_2$ plasma treatment on Cu surface by using a 4-point bending test. The interfacial adhesion energy and bonding quality depend on increased bonding temperature and post-annealing temperature. With increasing bonding temperature from $250^{\circ}C$ to $350^{\circ}C$, the interfacial adhesion energy increase from $1.38{\pm}1.06$ $J/m^2$ to $10.36{\pm}1.01$ $J/m^2$. The Ar+$H_2$ plasma treatment on Cu surface drastically increase the interfacial adhesion energy form $1.38{\pm}1.06$ $J/m^2$ to $6.59{\pm}0.03$ $J/m^2$. The plasma pre-treatment successfully reduces processing temperature of Cu to Cu direct bonding.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.45-50
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• 2014

Effects of wet chemical treatment and thermal cycle conditions on the quantitative interfacial adhesion energy of $Cu/SiN_x$ thin film interfaces were evaluated by 4-point bending test method. The test samples were cleaned by chemical treatment after Cu chemical-mechanical polishing (CMP). The thermal cycle test between Cu and $SiN_x$ capping layer was experimented at the temperature, -45 to $175^{\circ}C$ for 250 cycles. The measured interfacial adhesion energy increased from 10.57 to $14.87J/m^2$ after surface chemical treatment. After 250 thermal cycles, the interfacial adhesion energy decreased to $5.64J/m^2$ and $7.34J/m^2$ for without chemical treatment and with chemical treatment, respectively. The delaminated interfaces were confirmed as $Cu/SiN_x$ interface by using the scanning electron microscope and energy dispersive spectroscopy. From X-ray photoelectron spectroscopy analysis results, the relative Cu oxide amounts between $SiN_x$ and Cu decreased by chemical treatment and increased after thermal cycle. The thermal stress due to the mismatch of thermal expansion coefficient during thermal cycle seemed to weaken the $Cu/SiN_x$ interface adhesion, which led to increased CuO amounts at Cu film surface.

• Corrosion Science and Technology
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• v.13 no.5
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• pp.186-194
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• 2014

Establishment of adhesion strength measurement procedure for marine epoxy coatings was conducted in order to ensure reliability of the test results. It was found that (1) the increase in thickness of the substrates would induce increase of pull-off strength. Especially, the increase in adhesion strength with the substrate thickness increment was attributed to the transition of stress mode to the pure tensile mode excluding bending effect. (2) The longer curing time, the higher pull-off strength. It may be due to higher cross-linking density of the coating (3) The pull-off strength increases as coating thickness increases due to the diminishment of bending effect (4) The longer drying time after water immersion, the higher pull-off strength. It may be due to the evaporation of water molecule at the coating-substrate interface.

• Carbon letters
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• v.28
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• pp.9-15
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• 2018

In the aerospace field, Carbon/Cork composites have been used for rocket propulsion systems as a light weight structural component with a high bending stiffness and high thermal insulation properties. For the fabrication of a carbon composite with a heat insulation cork part, the bonding properties between them are very important to determine the service life of the Carbon/Cork composite structure. In this study, the changes in the interfacial adhesion and mechanical properties of Carbon/Cork composites under accelerated aging conditions were investigated. The accelerated aging experiments were performed with different temperatures and humidity conditions. The properties of the aged Carbon/Cork composites were evaluated mainly with the interfacial strength. Finally, the lifetime prediction of the Carbon/Cork composites was performed with the long-term property data under accelerated conditions.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.110-114
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• 2011

Polymeric films of high chemical stability and mechanical strength covered with a thin metallic film have been extensively used in various fields as electric and electronic materials. In this study, we have chosen polypropylene (PP) as the polymer due to its outstanding chemical resistance and good creep resistance. We coated thin nickel film on PP films by the electroless plating process. The surfaces of PP films were pre-treated and modified to increase the adhesion strength of metal layer on PP films, prior to the plating process, by an environment-friendly process with atmospheric plasma generated using dielectric barrier discharges in air. The surface morphologies of the PP films were observed before and after the surface modification process using a scanning electron microscope (SEM). The static contact angles were measured with deionized water droplets. The cross-sectional images of the PP films coated with thin metal film were taken with SEM to see the combined state between metallic and PP films. The adhesion strength of the metallic thin films on the PP films was confirmed by the thermal shock test and the cross-cutting and peel test. In conclusion, we made a composite material of metallic and polymeric films of high adhesion strength.

• Corrosion Science and Technology
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• v.19 no.2
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• pp.51-56
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• 2020

The objective of this study was to improve properties of plasma sprayed HAp layer to titanium substrate by introducing an intermediate layer with two different methods. Before applying Zn doped HAp coating on titanium substrate, an intermediate layer was introduced by titanium plasma spray or titanium anodization. Heat treatments were conducted for some samples after titanium intermediate layer was formed. Zn doped HAp top layer was applied by plasma spraying. Three-point bending test and pull-off adhesion test were performed to determine the adhesion of Zn doped HAp coatings to substrates. Long-term credibility of Zn doped HAp plasma sprayed coatings on titanium was assessed by electrochemical impedance measurements in Hanks' solution. It was found that both titanium plasma sprayed and titanium anodized intermediate layer had excellent credibility. Strong adhesion to the titanium substrate was confirmed after 12 weeks of immersion for coating samples with titanium plasma sprayed intermediate layer. Samples with titanium anodized intermediate layer showed good bending strength. However, they showed relatively poor resistance against pulling off. The thickness of titanium anodized intermediate layer can be controlled much more precisely than that of plasma sprayed one, which is important for practical application.

• The Journal of the Korean dental association
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• v.58 no.1
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• pp.19-26
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• 2019

Purpose: The purpose of this study is to compare the adhesion of Candida albicans according to build angle in 3D printing denture base resin. Methods: The 3D printing was performed by setting the build angle of the disk type specimen designed by CAD program at 0 degree, 30 degrees, 60 degrees, and 90 degrees. Surface roughness was measured using a non-contact 3D microsurface profiler. The specimens were incubated in Candida albicans suspension for 24 hours. The attached Candida albicans were detached by cell scraper. The suspension of detached C. albicans was serially diluted and plated on Trypticase soy broth. After 48 hours of incubation, total colony forming unit was counted. Results: There was no significant difference in surface roughness(Sa) between the test groups, but the interlayer boundary was observed. There was no statistically significant difference in total colony forming units of Candida albicans between the test groups. Conclusion: There was no difference in the average surface roughness and adhesion of Candida albicans between the specimens. It is considered that the setting of the build angle should be set considering the accuracy or strength rather than the roughness of the surface.