• Composites Research
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• v.29 no.5
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• pp.243-248
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• 2016

Although thermoset carbon fiber composite bipolar plates not only have high mechanical properties but also high corrosion resistance in acid environment, high manufacturing cost and low bulk electrical conductivity are the biggest obstacle to overcome. In this research, thermoplastic polymer is employed for the matrix of carbon composite bipolar plate to increase both the manufacturing productivity and bulk electric conductivity of the bipolar plate. In order to increase the electrical conductivity and strength, plain type carbon fabric rather than chopped or unidirectional fibers is used. Also nano particles are embedded in the thermoplastic matrix to increase the bulk resistance of the bipolar plate. The area specific resistance and the mechanical strength of the developed bipolar plate are measured with respect to the environmental temperature and stack compaction pressure.

• The Research Journal of the Costume Culture
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• v.26 no.5
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• pp.754-763
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• 2018

This study examined the color reproducibility and color fastness of digital textile printing for nylon sublimation transfer. After measuring the temperature and time suited to nylon sublimation transfer, the researchers conducted various tests for comparison and analysis including polyester transfer paper on polyester fabric to check dyeing characteristics, color change, sharpness, and the rubbing fastness of the dyeing samples for nylon sublimation transfer. These tests produced the following results. At $185^{\circ}C$ and $187^{\circ}C$, the sublimation transfer dyeing characteristics of nylon were similar to those of polyester and the researchers even observed superior color development in some colors; at a low temperature of $180^{\circ}C$, the sample that was worked on had the lowest level of color development. The examination of color difference (${\Delta}E$), which compared $L^*a^*b^*$ values, showed that the ${\Delta}E$ value of magenta was 10.34, that of yellow was 24.70, and that of black was 15.28. These results highlight the important role of heat treatment temperature and time on color development in nylon sublimation transfer. Concerning sharpness, the samples subjected to higher temperature heat treatment exhibited fewer color spreading phenomena around lines. Thus, dyeing properties and fastness can be enhanced by elongating time at low temperatures and shortening time at high temperatures; however, considering production time constraints as well as the need to produce industrially marketable quantities, the findings of this study suggest that the heat treatment temperature most suitable for nylon sublimation transfer is $187^{\circ}C$ for a duration of 50 seconds.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.193-198
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• 1998

This paper presents the effects of an initial braking velocity, a braking pressure, and the number of braking stop on the tribological behaviors for the three different C-C composites using an inertia dynamic-friction tester. The C-C composites were prepared through the processes of several cycles of pitch impregnation/carbonization with different friction surface texture such as continuous 8-harness satin fabric (ADD-1), chopped fiber (ADD-2) and chopped fiber (ADD-3) having higher fiber volume fraction on friction than ADD-2 by about 10%. ADD-1 exhibited a higher fraction coefficient (0.41~0.33) than those of ADD-2 and ADD-3 (0.32~0.26) under the various initial braking velocities and braking pressures. The fraction coefficients decreased with increasing the initial velocity and the braking pressures. Wear rate by the thickness change after every 25 stop indicated that ADD-2 and ADD-3 having 1.7~2.7 $\mu\textrm{m}$/stop/pair were much lower than that of ADD-1 showing 5.0~6.5 $\mu\textrm{m}$/stop/pair. All specimens showed a little bit lower wear rate during the middle stage than the initial and latter stages among 100 braking stops. ADD-1 showed higher friction coefficient and wear rate due to the active pull-out of the fibers, evidenced by thicker were film and wear debrises.

• Polymer(Korea)
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• v.26 no.2
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• pp.153-159
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• 2002

In order to remove $NO_3;^-$ ion from ground-water, fibrous ion -exchangers, APP-g-GMA, were synthesized by GMA grafting onto PP trunk polymer with E-beam accelerator for pre-irradiation. Their degrees of grafting and amination yield increased up to $60^{\circ}C$ and showed maximum values as 133%, 88%, respectively. And their swelling ratio and ion exchange capacity at the maximum values are 86%, 2.5 meq/g, respectively which was higher than commercial ion-exchangers such as IMAC HP555 and Amberlite IRA 400. Optimum adsorption condition of $NO_3;^-$ ion was measured at pH 5~6 and -Cl form of APP-g-GMA containing trimethylammonium group showed the highest adsorption capacity.

• Polymer(Korea)
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• v.25 no.1
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• pp.49-55
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• 2001

The bi-functional ion exchangers, SAPP-g-(AN/St) were synthesized with mixed vinyl monomers(acrylonitrile and styrene) onto PP fabric by the pre-irradiation grafting with E-beam and its subsequent amidoximination and sulfonation. The degree of grafting of PP-g-(AN/St) was increased with decreasing acrylonitrile composition in the mixed monomers. The water uptake of copolymers increased with decreasing in the amidoxime ratio in the copolymers and increased by sulfonation, but decreased by amidoximation. The $UO_2^{2+}$ adsorption capacity of SPP-g-St, APP-g-AN, and SAPP-g-(AN/St) were 12.4, 34.0, and 38.0 mg/g, respectively and the optimum adsorption time is about 50 hrs. As a result of uranium adsorption, the synthesized ion exchanger, which we obtained have also good affinity toward the adsorption or chelating with $UO_2^{2+}$ ions.

• Polymer(Korea)
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• v.24 no.1
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• pp.1-7
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• 2000

The ACF/PP-g-AAc copolymers were synthesized by the irradiational grafting of acrylic acid onto ACF/PP fabric. The synthesis of copolymer was evidenced by the bands at 1720, 3600~3100 $cm^{-1}$ / on FT-IR spectrum. After the adsorption of metal ions on ACF/PP-g-AAc copolymers, the morphology with the small deposits on the fiber surface were observed by SEM. The optimal time for the metal ion adsorption equilibrium on ACF/PP-g-AAc copolymers was 24 hrs and their adsorption capacities increased in the order of Mn$^{2+}$>Cu$^{2+}$>Co$^{2+}$>Ni$^{2+}$. The adsorption capacities of ACF/PP-g-AAc copolymers were invariable after more than 10 times of regeneration.eration.

• Membrane Journal
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• v.16 no.2
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• pp.85-105
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• 2006

Poly(lactic acid) is a linear aliphatic thermoplastic polyester, produced by the ring-opening polymerization of lactides and the lactic acid monomers, which are obtained from the fermentation of sugar feed stocks, corn, etc. PLA has high mechanical, thermal plasticity, fabric-ability, and biocompatibility, So PLA is a promising polymer far various end-use applications. In recent time, the intercalation of polymers from either solution or the melt in the silicate galleries of clay is the best technique to prepare nanocompoiste material which often exhibit remarkable improvement of mechanical, thermal, optical and physicochemical properties when compared with the pure polymer or conventional composites. Layered silicate is naturally abundant, economic, and more importantly benign to the environment.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.2
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• pp.213-221
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• 2009

This study provides the optimum papain treatment method and its effect on wool/polyester blend fabrics. The enzymatic treatment condition is optimized depending on its pH level, temperature, concentration of enzyme, treatment time and concentration of activators. The characteristics of samples treated with the papain are measured using weight loss, tensile strength, whiteness, WCA, dyeing property and surface micrographs. The results are described as follows: According to measuring weight loss, tensile strength and whiteness, a pH level of 7.5, $70^{\circ}C$, 10% papain(o.w.f.) and 60minutes of treatment time are optimized for papain treatment. L-cysteine and sodium sulfite are able to activate the papain. The optimum concentrations of them are 10mM and 50mM respectively. The WCA of fabrics is decreased since papain treatment makes wool/polyester blend fabrics more hydrophilic. Scouring with papain treatment improves whiteness and dyeing property of fabrics. The dyeing property of papain-treated fabrics is enhanced simply by a single step dyeing process using a basic dye. The surface of wool treated with papain in the presence of L-cysteine shows to be descaled. The surface of wool fibers in the presence of sodium sulfite, however, shows it is hydrolyzed evenly instead of being descaled. The surface of papain treated polyester fibers shows cracks and voids.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.458-467
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• 2017

There is increased interest in clothes dryers and garments made of spandex-blend woven fabrics; however, there is limited information available for the laundering and drying these clothes. This study investigates the effects of washing and drying on shrinkage, skewness, and wrinkle for woven fabrics with and without spandex. When spandex with good elastic recovery was blended, the deformed shape from washing and drying improved skewness and wrinkle by easily returning to its original shape. However, these properties had a negative effect on shrinkage in terms of length and area change. When the influence of clothes maintenance was classified, the drying process had the biggest influence of 58%, followed by spinning-rinsingwashing. Tumble drying, in which the fabric is exposed to mechanical force and heat for a long period, had more negative effects on the dimensional stability than line drying. The spandex blend had the effect of preventing skewness and wrinkle in garments, but it was also shown to accelerate shrinkage by garment maintenance cycles. It was important to control drying in order to reduce shrinkage during the maintenance process; consequently, this had the greatest influence on the dimensional stability of fabrics. Therefore, line drying was more advantageous for spandex-blend fabrics than tumble drying in terms of management for shrinkage, skewness, and wrinkle.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.623-629
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• 2007

Recently, the $"Optim"^{(R)}$ which is the wool fibre with high lustre developed by CSIRO in Australia is imported and commercialized as a high sensible fabrics for garment. But the price of this $"Optim"^{(R)}$ fibre is very high so material demand and supply is not smooth. This study is aiming to develop the drawing technology of the worsted yarn with washable function, lustre and low production cost. For this purpose, drawing yarns are made using developed drawing machine and high sensible fabrics are woven using this yarns, and various physical properties of the fabric specimen are measured and analysed with garment characteristics such as sewability and formability. The final objective of this study is seemed to be achieved by making the high sensible fabrics using drawing worsted yarns with high lustre such as $"Optim"^{(R)}$ fibre.