• Title/Summary/Keyword: Fiber chain

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Additive Effects in Living Cationic Polymerization of tort-Butyl Vinyl Ether, initiated by Iodine

  • Jeon, Hyunjeong;Kwon, Soonhong;Han, Kyuchan;Mah, Soukil
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.90-90
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    • 2003
  • Living nature was appeared in the cationic polymerization of tort-butyl vinyl ether (TBVE), initiated by iodine, carried out in toluene at -78$^{\circ}C$. It was found that the number average molar mass of the resulting polymer (equation omitted) increases linearly as the conversion to polymer increase which reveals that there is no operation of chain transfer or termination process in this system. The polymers having narrow distribution and having molar mass of the resulting polymers are dependent on molar ratio of monomer and iodine.

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Ferroelectric P(VDF/TrFE) Copolymers in Low-Cost Non-Volatile Data Storage Applications

  • Prabu A. Anand;Lee, Jong-Soon;Chang You-Min;Kim, Kap-Jin
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.237-237
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    • 2006
  • P(VDF/TrFE(72/28) ultrathin films were used in the fabrication of Metal-Ferroelectric polymer-Metal (MFM) single bit device with special emphasis on uniform film surface, faster dipole switching time under applied external field and longer memory retention time. AFM and FTIR-GIRAS were complementary in analyzing surface crystalline morphology and the resultant change in chain orientation with varying thermal history. DC-EFM technique was used to 'write-read-erase' the data on the memory bit in a much faster time than P-E studies. The results obtained from this study will enable us to have a good understanding of the ferroelectric and piezoelectric behavior of P(VDF/TrFE)(72/28) thin films suitable for high density data storage applications.

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PHOTOINDUCED PHASE TRANSITION BEHAVIOR OF LIQUID CRYSTALLINE COPOLYMERS CONTAINING AZO CHROMOPHORE

  • Kang, Suk-Hoon;Samui, Asit-Baran;Choi, Dong-Hoon
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.28-31
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    • 1998
  • Photoresponsive polymers are being intensely investigated over last two decades, which can be attributed to both fundamental and applied significance. Presently the attention is being directed to these materials in view of their possible application in nonlinear optics and optoelectronics. It was demnstrated quite early that by covalent fixation of both photochromic group and the mesogenic group to the same polymer main chain high concentration of photochromic group can be attained.(omitted)

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Synthesis of Liquid Crystalline Copolyurethanes Containing Imide Unit

  • Lee, Dong-Jin;Lee, Tae-Jung;Kim, Han-Do
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.94-97
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    • 1998
  • We have been studying :he synthesis of thermotropic polyurethanes, based on structural modifications by means of (i) the introduction of bulky substituent group in the aromatic ring to decrease the degree of lateral packing, (ii) the copolymerization of two kinds of monomers having different alkylene lengths to lower the regularity of the polymer structure, and (iii) the use of nonlinear monomers to lower the persistence length of the polymer chain in the liquid crystalline phase and to decrease the lateral interactions in the solid state. (omitted)

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A Study on the Change of Spandex Quality by the Influence of Dyeing Condition (스판덱스섬유(纖維)의 염색조건(染色條件)이 섬유품질(纖維品質)에 미치는 영향(影響))

  • Park, Byeong-Gi
    • Journal of Korean Society for Quality Management
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    • v.9 no.1
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    • pp.22-39
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    • 1981
  • Spandex is a elastomeric fiber in which the-fiber-forming substance is a long chain polymer consisting of at least 85% segmented polyurethane. In the polyurethanes there are the additional oxygen atoms in the main chains of the molecule. The effect of these oxygen atoms is to make the molecule somewhat more flexible. From a physical point of view, elasicity and recovery from stretch are the most important properties of polyurethane, so its use has now expanded into many kitting industry. In this paper, I wish to Test the effect of dyeing condition on the quality of polyurethane.

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A STUDY ON THE LYOTROPIC LIQUID CRYSTALLINE COPOLYAMIDE

  • Lee, Chul-Joo;Min, Byoung-Gill;Son, Tea-Won;Yoon, Han-Sik
    • Proceedings of the Korean Fiber Society Conference
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    • 1987.06b
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    • pp.12-12
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    • 1987
  • To improve the fibrillation phenomenon and processibili to of poly(p-phenyleneterephthalamide) (PPD-T) , a P/E copolyamide was prepared by introducing 4,4'-ethylene dianiline (EDA) into rigid chain backbone. The effects of semi-flexible segment on the liquid crystalline properties were investigated. The EDA, used as a comonomer, was prepared by catalylitic reduction of p,p'-dinitrophenyl , obtained by oxidative coupling of p,p'-dinitrotoluene. Various high molecular weight PIE copolyamides were prepared by low temperature solution polycondensation of terephthaloyl chloride (TPC) with various mixtures of p-phenylene diamine (PPD) and EOA. The PfE copolyamides were completely dissolved in 100% svlfuric acid, and the phase transition of P/E copolyamide-sulfuric acid systems was examined in teams of concentration and temperature. Over the chemical compositions, PIE=911, 812, and 713, solutions of anisotropic single phase were acquired. In particular, the two mixing ratios, 911 and 812, gave a good anisotropic spinning dope.

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Gain dynamics of erbium-doped fiber amplifiers and suppression of power transients (에르븀 첨가 광섬유 증폭기의 이득 동특성과 과도 현상의 억제)

  • 박서연;김향균;신상영
    • Korean Journal of Optics and Photonics
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    • v.8 no.6
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    • pp.471-475
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    • 1997
  • We investigate the gain dynamics of erbium-doped fiber amplifiers during single- and multi-channel amplification. Power transients due to the changes in the number of channels in the amplifier chain are measured. We successfully suppress power transients by using a fast pump control circuit with<$\mu$s response time.

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Effects of Heat Treatment on Electrical and Mechanical Properties of Glass Fiber Reinforced Epoxy (열처리가 유리섬유 강화 복합재료의 전기적 및 기계적 성질에 미치는 영향)

  • 이백수;이덕출
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.3
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    • pp.174-180
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    • 1998
  • In this work, the properties of FRP, which is applied recently in the composite insulating materials, by thermal treatment were investigated. The specimens were epoxy glass laminates fabricated by thermal press method and had the volume content of 46[%] cutted $45^{\circ}C$ in the fiber direction and 1.0[mm] thickness. The experimental results showed that the amount of weight loss, wettability, surface potential, and surface resistivity increased up to 200[$^{\circ}C$] as a function of temperature. Usually, most degradations caused the hydrophilic to decrease the contact angle. But, in this work on thermal-degradated FRP, we can confirm the introduction of hydrophobic properties by cross-linking and the ablation of polar small-molecules rather than chain scission and oxidation. Finally, weight loss and contact angle increased. These phenomena show the existence of hydrophobic surface. With the change to the hydrophobic surface and the electrical potential and resistivity on FRP surface increased. But, the dielectric properties and tensile stength are decreased.

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A Case Study on Implementing SCM to Textile Fashion Industry as Small Business (섬유패션 중소기업의 SCM 사례 연구 - 커튼업체를 중심으로 -)

  • Shin, Sang-Moo;Choe, Jin-Hyeok
    • Journal of Fashion Business
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    • v.12 no.5
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    • pp.155-167
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    • 2008
  • With globalization and competitive market environment, companies realize how marketing channels are important in order to survive and succeed the business. The importance of information management among channels is getting increased, and is needed for SCM. Nevertheless having hard situation to implement SCM, SCM for textile fashion industry engaged in small business mostly is the way to break through the difficulty on so many channels to go through from fiber to retail. Therefore, the purpose of this case study to L firm by using questionnaire based interviewing method was to investigate how textile fashion small business can implement the SCM with their own differentiated strategy differed from a large corporation. L firm conducted SCM-ISN (Information Service Network) under the restructuring project. So they could use electronic bidding system via internet and have information sharing with their partners such as retailers. Therefore, they could expand market share to Seoul and reduce inventory and manage their customer more effectively than before.

The Empirical Research on Underwear Products Strategies According to Consumer's Purchasing Characteristics of Sex (소비자의 성별 구매특성에 따른 내의류 제품전략에 대한 실증연구)

  • Choi, Kyeong-Eun
    • Korean Journal of Human Ecology
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    • v.9 no.4
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    • pp.41-53
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    • 2006
  • The purpose of this study was to compare the characteristics of underwear consumer's underwear purchasing behavior through survey. 630 questionnaires were distributed in Seoul and Chonju and 618 with usable data were analyzed frequency and factor analyses, t-test etc. using SPSSWIN 10.0. program. The results were summarized as follows : Most male consumers buy underwears at discount stores whereas most female consumers at chain store. Throughout all four seasons, more male and female consumers do not wear heat-retaining underwears. Most male and female consumers do not have function-fiber underwears nor functional-finishing and natural-dyeing-treated underwears. Most consumers are not satisfied with these underwears. The most important criteria for most male consumers to choose underwears are comfort levels while in action, the sense of touch, comfort levels while wearing them while not in action, pleasance levels; whereas for females are comfort levels while in action, and comfort levels while wearing them while not in action. Male consumers prefer a little bigger-than-their-bodies size, dry and soft fabrics, plain white color; whereas female consumers prefer a little tight size, dry and soft fabrics and plain beige color, Most consumers want to buy functional-fiber underwears made of yellow- soil-and-charcoal-dyeing fabrics which has jade.

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