• Analytical Science and Technology
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• v.30 no.4
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• pp.213-219
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• 2017

Polyalkylsiloxane has been spotlighted in pressure-sensitive adhesive (PSA) application due to excellent physical properties and good biocompatibility. Thermal behaviour of polyalkylsiloxane mixtures, such as thermal stability and heat flow, were studied using TG-DTA during catalytic hydrosilation. To understand reaction kinetics of cross-linking, catalytic hydrosilation of polyalkylsiloxane was monitored using variable temperature nuclear magnetic resonance (VT-NMR) as increased temperature. The formation of cross-linking bond $Si-CH_2-CH_2-Si$ was directly observed using distortionless enhanced by polarization transfer (DEPT) technique. Successfully polyalkylsiloxane PSA samples exhibited excellent adhesion properties by cross-linking reaction.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.155-163
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• 1989

Indirect bonding is done by placing the brackets on a model in the laboratory and using a template or tray to transfer the laboratory positioning to the teeth. The advantages of this technique are 1. decreased chair time 2. less patient discomfort 3. accuracy of a attachment placement 4. good adaptation of attachment to tooth contour 5. occlusal relationship of brackets and opposing teeth can be checked The disadvantages of the technique are 1. complex laboratory procedure 2. sometimes difficult on very short clinical crowns 3. teeth with crowns, large buccal restoration will not bond 4. may not be fitted close, if poor adaptation 5. likely to be disturbed setting Several indirect bonding techniques have proved reliable in clinical practice. However, they differ in the way the brackets are attached temporarily to the model, the type of transfer tray or other mechanism used, the adhesive or sealant employed, whether segmented or full bonding used, and the way the transfer is removed so as not to exert excessive force on a still maturing bond.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.16-23
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• 2001

Comparing with general optical fiber sensors performing localized measurement, distributed optical fiber sensors can measure along an optical fiber, and they have large measuring range. The surface-mounting method with epoxy adhesive is general in attaching optical fiber sensors to structures, This is also appliable to the structural integrity monitoring with Brillouin-scattering distributed optical fiber sensors. In this paper, Brillouin-scattering distributed optical fiber sensors, which are attached to the surface of a structure with epoxy adhesive, was verified with the finite element method. From the analysis results of strain transfer through the structure, optical fiber coating, cladding and core, the strain transfer rates were calculated. And the influence of the epoxy free-end was also studied.

• Journal of Adhesion and Interface
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• v.17 no.2
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• pp.49-55
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• 2016

In this study, we designed an environment friendly, water-based adhesive using the acrylic emulsion method as a replacement for solvent-based adhesives, which are most commonly used in layered laminates for flexible food packaging. We designed adhesives with different combinations of anionic, non-ionic, and phosphoric ester surfactants, and with different concentrations of chain transfer agent (CTA). We also examined the effect of the degree of cross-linking by synthesizing and comparing 8 test group adhesives with different types of functional monomers. Additionally, we synthesized 2 other test group pressure-sensitive adhesives (PSA) using styrene/alpha-methyl styrene/acrylic acid (SAA) semipolymer dispersing agents (with molecular weights of 13,000 g/mol and 8,600 g/mol, respectively) to replace the conventional surfactants. We evaluated whether the 10 test group pressure-sensitive adhesives met the basic physical property criteria required for flexible food packaging by carrying out a physical analysis of their glass transition temperature (Tg), particle size, adhesion, and molecular weight. In our test, 2 test group adhesives manufactured with the combination of anionic and non-ionic surfactants, CTA concentration of 0.2%, and functional monomers of hydroxyethyl acrylate (HEA) and glycidyl methacrylate (GMA) demonstrated molecular weight and flexibility suitable for flexible packaging, with low adhesiveness and small particle size.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1388-1393
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• 2003

In this study, analytic stress-displacement solutions are obtained by using a shear lag modeling constructed for the spliced joint area with a splicing gap filled with adhesive material of elastic modulus $E_{a}$ in the fiber metal laminate (FML) which is known to have excellent fatigue, corrosion and fire-flame resistant characteristics while with relatively low densities compared to the conventional aluminum alloys for lightweight structures.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.2 s.233
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• pp.220-227
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• 2005

In this study, stress-displacement analytic solutions are obtained by a shear lag modeling method constructed for the spliced joint area with a splicing gap in the fiber metal laminate (FML). This gap can be empty or be filled with an adhesive material of elastic modulus $E_a$. Two splicing types are considered for spliced shear models, one for spliced in the center metal layer, the other for spliced in the outer metal layer. It is shown that from the viewpoint of the load transfer efficiency and the avoidability of disbond generation due to the shear and axial stresses at the interface between metal layer and composite layer of the gap-front in the spliced area, the center spliced type (k=2) is much preferable to the outer spliced type (k=1).

• Journal of Adhesion and Interface
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• v.23 no.3
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• pp.80-86
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• 2022

In this study, water-based acrylic tackifier with different contents of 1-dodecanethiol(n-DM), a chain transfer agent(CTA), were synthesized to improve the performance and adhesive properties of water-based acrylic pressure sensitive adhesive(PSA). In order to investigate the change in physical properties according to the amount of water-based acrylic tackifier added, 10/20/30 phr of water-based acrylic tackifier was added to the water-borne acrylic emulsion to measure the physical properties. The molecular weight and glass transition temperature(T_g) of the synthesized water-based acrylic tackifier tended to decrease as the content of n-DM increased. When a water-based acrylic tackifier was added to the water-borne acrylic emulsion, the peel strength and heat-resistance were increased. Also, when the water-based acrylic tackifiers were added at 10 phr or 20 phr, the best value was shown.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.2
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• pp.73-82
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• 2004

A thermal transfer method was developed novel method to form the phosphor screen for monochrom VPT. This method have advantages of simple process, clean environment, saving raw material and running-cost. But now applying phosphor screen for thermal transfer method has been formed three layers (phosphor layer, ITO layer and thermal adhesive layer) on the PET film as substrate. This is complex process, consumption of raw-material and require of high cost. Also ITO paste at present has been imported from Japan. To improve these problems, we have developed ITO paste as conductive paste by using ITO sol and binder resin (AA3003). Ito paste as developed in this study has both conductive and excellent thermal transfer abilities. Thus we could manufacture phosphor screen formed two layers (phosphor layer and ITO layer).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.599-602
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• 2002

A novel rapid prototyping (RP) process, an automated transfer type variable lamination manufacturing process (Automated VLM-ST) has been developed. In Automated VLM-ST, a vacuum chuck and linear moving system transfer the plate type material with two pilot holes to the rotation stage. A four-axis synchronized hotwire cutter cuts the material twice to generate Automated Unit Shape Layer (AUSL) with the desired width, side slopes, length, and two reference shapes in accordance with CAD data. Each AUSL is stacked on the stacking plate with two pilot pins using the pilot holes in AUSL and the pilot pins. Subsequently, adhesive is supplied to the top surface of the stacked AUSL by a bonding roller and pressure is simultaneously applied to the bottom surface of the stacked AUSL. Finally, three-dimensional shapes are rapidly fabricated. This paper describes the procedure for generating the cutting path data (AUSL data) f3r automated VLM-ST. The method for the generation of the Automated Unit Shape Layer (AUSL) in Automated VLM-ST was practically applied and fabricated for a various shapes.

• International Journal of Concrete Structures and Materials
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• v.6 no.2
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• pp.123-134
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• 2012

There is significant concern in the engineering community regarding the safety and effectiveness of fiber-reinforced polymer (FRP) strengthening of RC structures because of the potential for brittle debonding failures. In this paper, previous research programs conducted by other researchers were reviewed in terms of the debonding failure of FRP laminates externally attached to concrete. This review article also discusses the influences on bond strength and failure modes as well as the existing experimental research and developed equations. Based on the review, several important conclusions were re-emphasized, including the finding that the bond transfer strength is proportional to the concrete compressive strength; that there is a certain bond development length that has to be exceeded; and that thinner adhesive layers in fact lower the chances of a concrete-adhesive interface failure. It is also found that there exist uncertainty and inaccuracy in the available models when compared with the experimental data and inconsistency among the models. This demonstrates the need for continuing research and compilation of data on the topic of FRP's bond strength.