• Title/Summary/Keyword: polymer fibers

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A Study on the Improvements of Strengths of Water-Permeable Concrete (투수성 콘크리트의 강도개선에 관한 연구)

  • 은재기;이철웅;김완기;조영국;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.307-312
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    • 1999
  • The purpose of this study is to ascertain the strength properties of water-permeable concrete with redispersible polymer powder, silica fume and polypropylene fibers. The water-permeable concrete using rediapersibel polymer powder with a water-cement ratio of 25%, polymer-cement ratios of 0 to 10%, silica fume contents of 0 to 10% and fiber contents of 0 to 1.5% are prepared, and tested for flexural strength, compressive strength and water permeability. From the test results, improvements in the strength properties of the water-permeable concrete due to the addition of the redispersible polymer powder, silica fume and fibers are discussed. It is concluded from the test results that the superior flexural and compressive strengths of water-permeable concretes are obtained at a propylene fiber content of 1.0% with a void filling ratio of 50%. And, the water-permeable concrete having a flexural strength of 15.6~28.4kgf/$\textrm{cm}^2$, a compressive strength of 63.5~120.6kgf/$\textrm{cm}^2$, and a coefficient of permeability of 1.14~1.70cm/s at a void filling ratio of 30% can be prepared. Also water-permeable concrete having a flexural strength of 35.6~57.9kgf/$\textrm{cm}^2$, a compressive strength of 164.0~290.0kgf/$\textrm{cm}^2$, and a coefficient of permeability of 0.19~1.04cm/s at a void filling ratio of 50% can be prepared in the consideration of the mix proprotioning factors.

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Effects of E-beam treatment on the interfacial and mechanical properties of henequen/polypropylene composites

  • Cho, Dong-Hwan;Lee, Hyun-Seok;Han, Seong-Ok;Drzal, Lawrence T.
    • Advanced Composite Materials
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    • v.16 no.4
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    • pp.315-334
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    • 2007
  • In the present study, chopped henequen natural fibers without and with surface modification by electron beam (E-beam) treatment were incorporated into a polypropylene matrix. Prior to composite fabrication, a bundle of raw henequen fibers were treated at various E-beam intensities from 10 kGy to 500 kGy. The effect of E-beam intensity on the interfacial, mechanical and thermal properties of randomly oriented henequen/polypropylene composites with the fiber contents of 40 vol% was investigated focusing on the interfacial shear strength, flexural and tensile properties, dynamic mechanical properties, thermal stability, and fracture behavior. Each characteristic of the material strongly depended on the E-beam intensity irradiated, showing an increasing or decreasing effect. The present study demonstrates that henequen fiber surfaces can be modified successfully with an appropriate dosage of electron beam and use of a low E-beam intensity of 10 kGy results in the improvement of the interfacial properties, flexural properties, tensile properties, dynamic mechanical properties and thermal stability of henequen/polypropylene composites.

A Study of Atmospheric Plasma Treatment on Surface Energetics of Carbon Fibers

  • Park, Soo-Jin;Chang, Yong-Hwan;Moon, Cheol-Whan;Suh, Dong-Hack;Im, Seung-Soon;Kim, Yeong-Cheol
    • Bulletin of the Korean Chemical Society
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    • v.31 no.2
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    • pp.335-338
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    • 2010
  • In this study, the atmospheric plasma treatment with $He/O_2$ was conducted to modify the surface chemistry of carbon fibers. The effects of plasma treatment parameters on the surface energetics of carbon fibers were experimentally investigated with respect to gas flow ratio, power intensity, and treatment time. Surface characteristics of the carbon fibers were determined by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Fourier transform infrared (FT-IR), Zeta-potential, and contact angle measurements. The results indicated that oxygen plasma treatment led to a large amount of reactive functional groups onto the fiber surface, and these groups can form together as physical intermolecular bonding to improve the surface wettability with a hydrophilic polymer matrix.

The Analysis of Surface Characteristics of the Hydrophilic Chemicals Treated PET Fibers using Tensiometric Methods (Tensiometric법을 이용한 친수하 PET 섬유의 표면특성 분석)

  • Chung Hae Won;Obendorf S. Kay
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.4 s.40
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    • pp.431-435
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    • 1991
  • The dispersion and Poiar force components of the surface free energy of PET fibers untreated and treated with hydrophilic chemicals, such as nonionic-soil release polymer (SRP), anionic, nonionic and hydrophilic silicone, were determined using harmonic-mean and geometric-mean methods. Contact angles of water and methylene iodide on the fibers were determined from the adhesion tensions using tensiometric method. Fibers treated with hydrophilic chemicals have the increased polar force component and the decreased dispersion force component. The adhesion tensions of triolein for the hydrophilic treated fibers were smaller than that for untreated fiber.

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Influence of Fluorinated Illite on Thermal, Antibiotic and Far-infrared Emission Properties of Polypropylene Non-woven Fibers (폴리프로필렌 부직포 섬유의 열, 항균 및 원적외선 방사 특성에 미치는 불소화 일라이트 첨가의 영향)

  • Kim, Jinhoon;Im, Ji Sun;Seo, Kyeong-Won;Lee, Young-Seak
    • Polymer(Korea)
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    • v.37 no.1
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    • pp.86-93
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    • 2013
  • In this work, the thermal, antibiotic properties and far-infrared emissivity of fluorinated illite embedded polypropylene non-woven fibers (f-illite/PP fibers) were investigated in the presence of 0, 1, 3, 5 and 7 wt% illite powders. The thermal properties of f-illite/PP fibers were studied by thermogravimetric analysis (TGA). Their antibiotic properties were examined by Staphylococcus aureus and Klebsiella pneumoniae test. Their far-infrared emissivity was also investigated by Fourier transform infrared spectroscopy. From the experimental results, thermal, antibiotic properties and far-infrared emissivity of f-illite/PP fibers were improved by increasing fluorinated illite contents and the property values of 5 wt% f-illite/PP fibers were increased remarkably by about 10.3, 41.2 and 9.8% respectively in comparison with PP non-woven fibers having no fluorinated illite additive. This result was interpreted as the development of interfacial adhesion force between the polymer chains due to the fluorination of illite power.

Preparation and Characterization of Electrospun Nanofibers Containing Natural Antimicrobials (천연 향균물질 함유 나노섬유의 제조 및 특성분석)

  • Kim, Young-Jin;Kim, Sang-Nam;Kwon, Oh-Kyoung;Park, Mi-Ran;Kang, Inn-Kyu;Lee, Se-Geun
    • Polymer(Korea)
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    • v.33 no.4
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    • pp.307-312
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    • 2009
  • The fabrication of PHBV nanofibers containing various plant polyphenols by electrospinning has been examined. It has been found that the average diameters of fibers increased by the adding of polyphenols. The resulting fibers exhibited a uniform diameter ranging from 340 to 450 nm. As the concentration of polyphenols increased, the diameter of fibers increased due to the hydrogen bonding interaction between the ester groups of PHBV and hydroxyl groups of polyphenols. The interaction between PHBV and polyphenols, which forms a complex together in solution, was verifed by UV measurement. ATR-FTIR analysis confirmed the existence of the hydrogen bonding interaction. The semicrystalline structure of the PHBV nanofiber was observed from XRD pattern. The crystallinity of PHBV nanofibers was increased by the adding of polyphenols. PHBV nanofibers containing polyphenols showed superior antimicrobial activities.

Preparation of Eco-friendly and High Strength Paper for Viscose Rayon Yarn (친환경 고강도 인견사용 종이 제조)

  • Hwang, Sung-Jun;Kim, Hyoung-Jin;Bae, Paek-Hyun
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.6
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    • pp.154-163
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    • 2015
  • Because of acute or chronic intoxication by carbon disulfide, viscose rayon industry is strictly subjected to environment regulatory approval. Recently, non-wood fibers are frequently considered as a raw materials for the manufacture of specialty paper for the higher physical strength and functionality. Among the non-wood fibers, hemp bast fiber is one of the most widely used materials in viscose rayon yarn industries. In this study, the handsheet for manufacturing the viscose rayon yarn was prepared with wood pulp fibers and hemp bast fibers. The proper mixing ratio of wood fibers and hemp bast fibers with dry-strength agent and nano-celluloses was analysed in terms of physical and mechanical strength of sheet for viscose rayon yarn. The papermaking conditions for high mechanical strength of sheet were obtained by mixing the SwBKP and HwBKP fibers with freeness level of 200 mL CSF. The dual polymer system by controlling the addition ratio of PVAm and anionic PAM was also important. The addition of nano-cellulose into wet-end furnishes increased the physical strength of sheet, and improved the paper structure for the production of viscose rayon yarn.