• Corrosion Science and Technology
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• v.4 no.5
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• pp.207-210
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• 2005

Coating performance of various coating systems including chlorinated rubber and epoxy/urethane used most for steel structures of highway in Korea, was evaluated by exposing test specimen to complex deterioration factors such as ultraviolet ray, moisture, freeze-thaw cycle and salt. Deteriorated specimens were evaluated by chalking and rust grades according to ASTM, and measurement of color differences and adhesion. In overall coating performances such as corrosion resistance, photochemical stability, and adhesion, ceramic/ urethane, moisture-curable urethane/ urethane, etc. were superior. As for other coating materials tested in this study, superior materials against certain deterioration factors may be inferior against other factors. Accordingly, in order to select suitable maintenance coating materials for the use, it is thought that investigation of suitability through experiment should precede selection of materials, especially for unusual coatings or paints.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.232-233
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• 2005

The Surface of semi-conductive silicone rubber was treated by oxygen plasma to improve adhesion and electric performance in joints between insulating and semi-conductive silicone materials. Surface characterizations were assessed using contact angle measurement and Fourier transform infrared spectroscope (FTIR). Adhesion level was understood from T-peel tests between plasma treated semi-conductive and insulating material. Electrical breakdown strength was measured to understand the charge of electrical performance. From the results, the oxygen plasma treatment produces a significant increase in function group of containing oxygen which can be mainly ascribed to the creation of carbonyl groups on the silicone surface from the strength were improved. Therefore it is concluded then plasma treatment leads to decrease voids originating form poor adhesive, and the improve the adhesion in silicone interface. So we could obtain higher electrical design level of silicone material used for electrical apparatus using oxygen plasma treatment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.226-227
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• 2019

Installation and usage methods are currently different between China and Korea for the same rubber asphalt waterproofing sealant. Quality verification is not properly carried out in this situation, so it is necessary to secure reliability in order to export domestic materials to China. In this study, rubber asphalt waterproofing sealant used as injection-type leakage repair material was tested in accordance to adhesion strength quality test method outlined in the JC/T2428 Chinese Industrial Standard to confirm the basic performance is compliant or not.

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.61-68
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• 2007

The applicable scope of adhesives in the current society is broad and currently, several types of PVAc resin are sold in the market for adhesives. PVAc resin is primarily used for wood works and paper adhesion. However, the PVAc resin itself has the disadvantages that its viscosity is highly temperature- dependent and the work condition and viscosity get worse at the low temperature in the winter seasons. Although phthalate-based plasticizer is used to complement these disadvantages, adhesion strength and heat-resistance are weakened by adding the phthalate-based plasticizer and in the winter period, the amount of quantity should be increased. Also in a high-density product, it worsens the work condition by causing a rise of viscosity and delays curing and in a low-density product, it worsens the storage stability by causing separate precipitation. In addition to these, the phthalate-based plasticizer as a material of causing environmental hormones is currently restricted in the advanced countries for its amount of use and also in the domestic market, it is necessary to prepare for the situation. This study has not only eliminated the disadvantages of PVAc resin emulsion without adding a phthalate-based plasticizer of causing these problems, but also synthesized the PVAc resin for timber adhesion that is excellent in woodwork, thermal-resistance, water-resistance, storage stability, and adhesion performance. As the result, it has proven an excellent performance in thermal resistance, water resistance, storage stability, and minimum film forming temperature.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.1-11
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• 2002

This study was conducted to investigate the effects of reaction pH conditions and hardener types on the reactivity, chemical structure and adhesion performance of UF resins. Three different reaction pH conditions, such as traditional alkaline-acid (7.5 → 4.5), weak acid (4.5), and strong acid (1.0), were used to synthesize UF resins which were cured by adding three different hardeners (ammonium chloride, ammonium citrate, and zinc nitrate) to measure adhesion strength. Fourier transform infrared (FT-IR) and carbon-13 nuclear magnetic resonance (¹³C-NMR) spectroscopies were employed to study chemical structure of the resin prepared under three different reaction pH conditions. Adhesion strength of the resins cured with three different hardeners was determined with lap shear specimens in tension. The gel time of UF resins decreased with an increasing in the amount of both ammonium chloride and ammonium citrate added in the resins. However, the gel time increased for zinc nitrate. Both FT-IR and ¹³C-NMR spectroscopies showed that the strong reaction pH condition produce uronic structures in UF resin, while both alkaline-acid and weak acid conditions produce quite similar chemical species in the resins. The maximum adhesion strength was occurred with the resin prepared under strong acid pH condition. However, this study indicated that the weak acid reaction condition provide a balance between increasing resin reactivity and improving adhesion strength of UF resin. The measurement of formaldehyde emission from the panels bonded with the UF resins prepared is planned for future work.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.176-181
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• 2018

Concrete structures are degraded physically and chemically due to various reasons after construction. Because the deterioration of concrete structure reduces the service life, reasonable repair and maintenance techniques are needed. Recently, in order to efficiently repair concrete structures, many researches on hybrid repair materials having improved adhesion performance have been carried out actively. In this study, we developed a hybrid repair material containing rapid hardening cement, PVA powder, nylon fiber, and latex to improve adhesion and water-tightness of existing concrete. The compressive strength, drying shrinkage and the adhesion strength test were carried out to evaluate the performance of the repair material. In addition, the flexure bond performance was evaluated before and after repair. From the results, the bending strength was 110% ~ 150% in all specimens except for the specimen containing only the rapid hardening cement, and all the specimens behaved with the existing concrete in the crack pattern generated by the bending strength.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.620-622
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has a slip state. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. First of all, this paper shows that conventional PI control can not be applied to a wheeled robot of the light weigh. Secondly, reposed fuzzy logic applied by the Takagi-Sugeno model for the configuration of fuzzy sets. For the design of Takaki-Sugeno model and fuzzy rule, proposed algorithm uses FCM(Fuzzy c-mean clustering method) algorithm. In additionally, this algorithm controls recovered driving torque for the restrain the re-slip. The proposed fuzzy logic controller(FLC) is pretty useful with prevention of the slip phenomena through that compare fuzzy with PI control for the controller performance in the re-adhesion control strategy. These procedures are implemented using a Pioneer 2-DXE wheeled robot parameter.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.357-361
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• 2006

The electrical performances of organic thin-film transistors (OTFTs) have been improved for the last decade. In this paper, it was demonstrated that the electrical characteristics of the organic thin film transistors (OTFTs) were improved by using polymeric material as adhesion layer on gate insulator. We have investigated OTFTs with polyimide adhesion layer which was fabricated by vapor deposition polymerization (VDP) processing and formed by co-deposition of 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 4,4'-oxydianiline. It was found that the OTFTs with adhesion layer showed better electrical characteristics than with bare layer because of good matching between semiconductor and gate insulator. Our devices of performance are field effect mobility of $0.4cm^2/Vs$, threshold voltage of -0.8 V and on-off current ratio of $10^6$. In addition, to improve the electrical characteristics of OTFT, we have reduced the thickness of adhesion layer up to a few nanometrs.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.7
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• pp.843-850
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• 2003

Cu/PET film composites were prepared by electroless copper plating method. In order to improve adhesion between electroless plated Cu layer and polyester (PET) film, the effect of pretreatment conditions such as etching method, mixed catalyst composition were investigated. Chemical etching and plasma treatment increased surface roughness in decreasing order of Ar＞HCl＞O$_2$＞NH$_3$. However, adhesion of Cu layer on PET film increased in the following order: $O_2$＜Ar＜HCl＜NH$_3$. It indicated that appropriate surface roughness and introduction of affinitive functional group with Pd were key factors of improving adhesion of Cu layer. PET film was more finely etched by HCI tolution, resulting in an improvement in adhesion between Cu layer and PET film. Plasma treatment with NH$_3$produced nitrogen atoms on PET film, which enhances chemisorption of Pd$^{2+}$ on PET film, resulting in improved adhesion and shielding effectiveness of Cu layer deposited on the Pd catalyzed surface. Surface morphology of Cu plated PET film revealed that Pd/Sn colloidal particles became more evenly distributed in the smaller size by increasing the molar ratio of PdCl$_2$; SnCl$_2$from 1 : 4 to 1 : 16. With increasing the molar ratio of mixed catalyst, adhesion and shielding effectiveness of Cu plated PET film were increased.d.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.70-71
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• 2005

The electrical performances of organic thin-film transistors (OTFTs) have been improved for the last decade. In this paper, it was demonstrated that the electrical characteristics of the organic thin film transistors (OTFTs) were improved by using polymeric material as adhesion layer on gate insulator. We have investigated OTFTs with polyimide adhesion layer which was fabricated by vapor deposition polymerization (VDP) processing and formed by co-deposition of 6FDA and ODA. It was found that the OTFTs with adhesion layer showed better electrical characteristics than with bare layer because of good matching between semiconductor and gate insulator. Our devices of performance are field effect mobility of $0.4cm^2$/Vs, threshold voltage of -0.8 V and on-of current ratio of $10^6$. In addition, to improve the electrical characteristics of OTFT, we have reduced the thickness of adhesion layer up to a few nanometrs.