• Journal of KSNVE
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• v.7 no.3
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• pp.411-418
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• 1997

A method to analyze the axisymmetric vibration and the internal pressure of the fluid filled, strength member embedded infinite cylindrical shell under the condition of axial static tension load applied is presented. As an example, the hose wall vibration and the internal pressure variation characteristics of a fluid filled infinite polyurethane hose are analyzed and dicussed, under the effects of the variation of the embedded strength members and the response positions.

• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.359-362
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• 2009

This study investigates the behavior of water vapor permeability of a layered system to find out a comfortable combination of a layered system for outdoor activities and examines the water vapor permeability of various types of outdoor clothing fabrics. The layered system includes the base layer such as sportswool and polyester/cotton fabrics, the middle layer such as single and double sided fleece fabrics, and the shell layer such as polyurethane-coated, PTFE-laminated and microfiber fabrics in this experiment. Results show that the layered system was applied, it was working together as a whole having some influence on each other layer, though every layer offered varying degree of water vapor permeability. Water vapor permeability of layered system exactly followed the same trend as the shell layer, which is all vapor permeable water repellent fabrics as a single layer. The rate of water vapor transfer through a layered system is mainly related to the type of vapor permeable water repellent fabrics used for the shell layer.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.66-66
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• 2003

야외 운동(outdoor activities)복에 사용되는 소재들은 외부로부터 신체를 안전하게 보호해 주어야 될 뿐 아니라 쾌적하게 유지시켜 주어야 한다. 의복착용시 쾌적감에 결정적인 영향을 미치는 인자는 몸의 열적 평형상태를 유지하기 위한 수단인 수분전달 특성이다. 본 연구는 여러 종류의 야외 운동복용 직물에서의 수분전달 현상을 조사하여 규명하므로써 이 직물들이 실제 의복생활에 응용될 의복계 (clothing system)를 형성하였을 때의 수분전달 현상을 설명하고자 하는 기초연구이다. 연구의 결과는 base layer용, mid layer용 직물들이 shell layer로 쓰이는 waterproof breathable 직물보다 수분 전달률이 높았으며, waterproof breathable 직물의 수분 전달률은 microfibre 직물, PTFE-laminated 직물 그리고 polyurethane coated 직물 순 이었다. 또한 polyurethane 직물에서는 back coated 직물이 face-coated 직물보다 수분 전달률이 높았다.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.192-196
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• 2003

야외 운동(outdoor activities)복에 사용되는 소재들은 외부로부터 신체를 안전하게 보호해 주어야 될 뿐 아니라 쾌적하게 유지시켜 주어야 한다. 의복착용시 쾌적감에 결정적인 영향을 미치는 인자는 몸의 열적 평형상태를 유지하기 위한 수단인 수분전달 특성이다. 본 연구는 여러 종류의 야외 운동복용 직물에서의 수분전달 현상을 조사하여 규명하므로써 이 직물들이 실제 의복생활에 응용될 의복계(clothing system)를 형성하였을 때의 수분전달 현상을 설명하고자 하는 기초연구이다. 연구의 결과는 base layer용, mid layer용 직물들이 shell layer로 쓰이는 waterproof breathable 직물보다 수분 전달률이 높았으며, waterproof breathable 직물의 수분 전달률은 microfibre 직물, PTFE-laminated 직물 그리고 polyurethane coated 직물 순 이었다. 또한 polyurethane 직물에서는 back coated 직물이 face-coated 직물보다 수분 전달률이 높았다.

• Journal of Adhesion and Interface
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• v.15 no.3
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• pp.109-115
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• 2014

In this study, we synthesized and identified microcapsule containing isocyanate, and investigated the mechanical and adhesion properties of polyurethane resin by adding microcapsule. We found out that the core material of microcapsule and the component weight fraction of microcapsule from the FT-IR and TGA analysis. From the results of adhesion and mechanical property tests, we confirmed that in case of using microcapsule for adhesive resin composition, adhesion strength, tensile strength and abrasion were improved by cross-linking reaction between urethane and IPDI in microcapsule.

• Macromolecular Research
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• v.14 no.4
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• pp.466-472
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• 2006

The kinetic behavior of emulsion polymerizations of styrene in the presence of sulfonated N-hydroxy ethyl aniline (SHEA) was investigated with two initiators: 2,2'-azobisisobutyronitrile (AIBN) and potassium persulfate (KPS). SHEA was synthesized using a stepwise polyurethane reaction method from 3-hydroxy-1-propane sulfonic acid sodium salt, isophorone diisocyanate (IPDI), and N-(2-hydroxyethyl) aniline. Stable core-shell poly(styrene/sulfonated N-hydroxy ethyl aniline, St/SHEA) latex particles were successfully prepared by using an appropriate amount of AIBN, in which SHEA plays the role of 'surfmer', i.e., acting as both a surfactant in the emulsion polymerization and a monomer in the chemical oxidative polymerization. The kinetic behavior was dissimilar to that of typical emulsion polymerization systems. A long inhibition period and low rate of polymerization were observed due to radical loss by the oxidative polymerization of SHEA. It was concluded, due to the low water-solubility of AIBN and retardation reaction by SHEA, that the initial loci of polymerization were monomer droplets. However, growing polymer particles as polymerization loci became predominant as polymerization proceeded. It was suggested that AIBN was more effective than KPS in the preparation of the core-shell type poly(St/SHEA) latex particles. With KPS, no substantial polymerization was observed in any of the samples.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.393-398
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• 2018

This work offers a promising approach for development of a temperature-responsive colorimetric display platform. For this purpose, uniform thermochromic microcapsules consisting of a cholesteric liquid crystal (CLC) core and a thin polyurethane shell layer were fabricated by conducting in-situ condensation polymerization at the interface of monodisperse CLC-in-water emulsion drops. Colloidal packing-driven microcapsule registry led to exact 2-dimensional positioning of CLC microcapsules into a holes-patterned flexible film stencil. Furthermore, we showed that the designated registry of different color types of CLC microcapsules on the stencil enabled development of a microwriting display technology capable of reversible text representation according to temperature change.

• Plant Journal
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• v.10 no.4
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• pp.35-41
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• 2014

The height and capacity of the thermal storage tank can be decided by the altitude and heat load of the heat supply area. Evaporation in heat pipe can be prevented by pressurizing it with the hydraulic head of the thermal storage tank. In addition, it absorbs the expanded volume from the temperature changes and supplies water to the pipelines in case of the shortage of water. One of the most important roles of the thermal storage tank is a stable heat supply facility. It can control the heat demand by accumulating the surplus heat and supplying in changing heat demand time. The purpose of this thesis is to be helpful for the operation and maintenance of the thermal storage tanks. The study has been carried out for 18 thermal storage tanks, which have been used polyurethane foam as insulation, among 27 tanks in district heating plants. The characteristics of the insulation materials, the reasons for the damages of the insulation and how impact the insulation damages to the corrosion of the thermal storage tank have been studied.

• Fibers and Polymers
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• v.7 no.1
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• pp.12-19
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• 2006

For thermal adaptable fabrics, the polyurethane-urea microcapsules containing phase-change materials (PCMs: hexadecane, octadecane and eicosane) were successfully synthesized by interfacial polycondensation using 2,4-toluene diisocyanate (TDI)/poly(ethylene glycol) (PEG400)/ethylene diamine (EDA) as shell monomers and nonionic surfactant NP-12 in an emulsion system under stirring rates of $3,000{\sim}13,000$ rpm. The mean particle size of microcapsule decreased significantly with increasing the stirring rate up to 11,000 rpm, and then leveled off. The mean particle size increased with increasing the content and molecular weight (eicosane > octadecane > hexadecane) of PCMs at the same stirring rate. The mean particle sizes of microcapsules were found to decrease with increasing the NP-12 content up to 1.5 wt%, and thereafter increased a little. It was found that the melting temperature ($T_m$) and crystallization temperature ($T_c$) of three kinds of encapsulated PCMs and their enthalpy changes (${\Delta}H_m,{\Delta}H_c$) increased with increasing PCM contents. The encapsulation efficiencies (Ee) of hexadecane microcapsule linearly increased with increasing the content of hexadecane. It was found that the stable microcapsule containing 50 wt% of hexadecane could be obtained in this study. However, Ee of octadecane and eicosane microcapsules increased with increasing PCM's contents up to 40 wt%, and then decreased a little. By considering the encapsulation efficiency, it was found that the maximum/optimum contents of octadecane and eicosane microcapsules were about 40 wt%. By the dynamic thermal performance test, it was found that the maximum buffering levels of Nylon fabrics coated with hexadecane, octadecane, and eicosane microcapsules were about $-2.4/+2.9^{\circ}C,\;-3.6/+3.6^{\circ}C\;and\;-4.0/+4.7^{\circ}C$, respectively.

• Textile Coloration and Finishing
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• v.34 no.4
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• pp.250-260
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• 2022

In this research, a high-elasticity acrylic emulsion binder with core-shell polymerization and self-crosslinking system is mixed with a flame-retardant water-dispersed polyurethane (PUD) binder. In addition, finite element analysis was conducted through virtual engineering software ANSYS by applying three representative nonlinear material models. The most suitable nonlinear material model was selected after the relative comparison between the actual experimental values and the predicted values of the properties derived from simulations. The selected nonlinear material model is intended to be used as a nonlinear material model for computational simulation analysis that simulates the experimental environment of the vibration test (ASTM E1399) and the actual fire safety test (ASTM E1966). When the mass fraction of thermally expandable graphite was 0.7%, the thermal and physical properties were the best. Among the nonlinear material models, the simulation result of the Ogden model showed the closest value to the actual result.