• Title/Summary/Keyword: NMMO/$H_2O$

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Parametric Study on the Morphology of Electrospun Cellulose Web (전기방사 조건이 셀룰로오스 웹 형상에 미치는 영향)

  • Jung, Yeon-Su;Jeong, Young-Jin
    • Textile Coloration and Finishing
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    • v.24 no.1
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    • pp.62-68
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    • 2012
  • Cellulose was electrospun over water collector and the cellulose solution was prepared using N-methyl-morpholine N-oxide/water(nNMMO/$H_2O$). The morphology of electrospun cellulose was investigated by scanning electron microscopy (SEM). SEM images showed that the fiber formation depended on processing parameters such as solution concentration, applied electric field strength, solution feeding rate and temperature of water in coagulation bath. High concentration, low temperature of water bath, and low feeding rate were more favorable to obtain fiber morphology. All the variables affected on the fluidity of the cellulose solution and diffusion of NMMO. Low fluidity and fast diffuision of NMMO was critical for obtaining fiber morphology.

Properties of Regenerated Cellulose Films Prepared from the Tunicate Styela clava (미더덕 껍질을 이용한 셀룰로오스 필름의 제조 및 특성)

  • Jung, Young-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.4
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    • pp.237-242
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    • 2008
  • The tunic of Styela clava(SCT) consists of a proteoglycan network. Regenerated cellulose films were prepared by solution casting and coagulation of SCT in N-methylmorpholine-N-oxide(NMMO)/$H_2O$(87/13 wt%). The crystalline structure of powdered SCT was primarily that of cellulose I. The crystalline structure of SCT films exhibited a cellulose II structure, similar to that of viscose rayon. Physical characterization of SCT films and fibers revealed an intrinsic viscosity($\eta$) of 6.35 dL/g, average molecular weight($M_w$) of 423,000 g/M, and fiber density of 1.50 $g/cm^3$ with a moisture regain and water absorption of 10.20% and 365%, respectively. The results were similar to those of cellulose films regenerated from wood pulp. Films prepared with 6 wt% SCT exhibited strong tensile strength, high water absorption, and a greater degree of elongation. Scanning electron micrographs(SEM) of film cross-sections showed a layered, sponge-like structure.

Preparation and Properties of Regenerated Composite Fibers made from Styela Clava Tunics/PVA Blending( II) (미더덕 껍질과 PVA를 혼합한 재료로부터 제조한 복합섬유의 제법과 성질(II))

  • Jung, Young-Jin;An, Byung-Jae;Kim, Hong-Sung;Choi, Hae-Wook;Lee, Eon-Pil;Lee, Jae-Ho;Kim, Han-Do;Park, Soo-Min;Kim, Sung-Dong
    • Textile Coloration and Finishing
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    • v.20 no.3
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    • pp.31-38
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    • 2008
  • Regenerated composite fibers were prepared from solution of styela clava tunics(SC) and poly vinyl alchol(PVA) using N-methylmorpholine-N-oxide(NMMO)/water(87/13)(wt%/wt%) as a solvent by dry jet-wet spinning. Structure and physical properties of regenerated composite fibers were investigated through birefrngence, x-ray diffratograms, tenacity, fibrillation and SEM. Optimal blend ratio of SC/PVA for mechanical properties of composite fibers was 70/30 and total weight was 4wt% concentrations in NMMO/$H_2O$ solvent system. Crystallinity index of composite fibers were decreased as the PVA contents increased. Fibrillation of $10{\sim}20wt%$ PVA blended fibers were occurred less than pure SC fiber. Shape of composite fibers were a circle cross section within 10wt% PVA content. But the cross section of fibers were changed as crushed flat with the PVA contents increased.