• Title, Summary, Keyword: polyurethane

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Observation of Surface Morphology and Electrical Properties of Polyurethane Polymer LB Films (폴리우레탄 고분자 LB막의 표면구조 관찰 및 전기적 특성)

  • Seo, Jeong-Yeul;Shin, Hoon-Kyu;Kwon, Young-Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.8
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    • pp.371-375
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    • 2001
  • We attempted to fabricate polyurethane derivatives (PU-CN, PU-DCM) LB films by using LB method. Also, we investigated the monolayer behavior at the air-water interface by surface pressure-area (${\pi}$-A) isotherms. The surface morphologies and the physicochemical properties of LB films were investigated by atomic force microscopy(AFM) and UV-vis spectroscopy, respectively. And, the electrical properties of polyurethane derivatives LB films were investigated by using the conductivity and the dielectric constant. In the surface morphologies, physicochemical and electrical properties of polyurethane derivatives LB films, the properties is different as to the polyurethane derivatives, it is considered that this phenomena could be described by the difference of lumophore pendant which was adhered at PU main chain.

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Chemical Structure Effect of Diisocyanate on the Coating Performance of Polyurethane-based Gel-coats

  • Park, Jin Hwan;Baek, Seung-Suk;Kim, Oh Young;Hong, Seheum;Park, Dong Hyup;Hwang, Seok-Ho
    • Elastomers and Composites
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    • v.54 no.1
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    • pp.30-34
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    • 2019
  • Four different diisocyanates (IPDI; isophorone diisocyanate, HDI; hexamethylene diisocyanate, HMDI; dicyclohexylmethane-4,4'-diisocyanate, and XDI; m-xylylene diisocyanate) were used to prepare polyurethane gel-coats, and the weatherabilities, physical properties, and surface characteristics of the gel-coats were investigated with respect to the chemical structure of the diisocyanates. The weathering test results indicated that all of the diisocyanates used in this study were suitable for use in the preparation of the polyurethane gel-coat. However, the set-to-touch times and physical properties of the polyurethane gel-coat indicated that the cycloaliphatic diisocyanate (IPDI and HMDI) were ideal for the preparation of polyurethane gel-coats.

A Fundamental Study on the Properties of Polyurethane Concrete (폴리우레탄 콘크리트의 기초적 성상에 관한 연구)

  • 강재홍;조영국;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.253-259
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    • 1996
  • The purpose of this study is to investigate the fundamental properties of polyurethan concrete. Polyurethane must be expanded by means of a blowing agent during polymerization. Chemical blowing is caused by the reaction water with isocyanate. Binder system for polyurethane concrete is based on polyol and isocyanate with catalyst, surfactant, and methyl chloride. Polyurethane concretes are prepared with various grading of aggregate, and tested for compressive, flexural strengths, flow test, foaming multiple proportion, working life, condition of surface, distirbution of aggregate. From the test results, the foaming of polyurethane concretes are affceted by amount and grading of aggregate. Workability increases with raising amount of methy chloride and working life reduced according to amount of catalyst. The mix proportion of B with methyl chloride of 1% and catalyst of 0.1g for polyurethane concrete is recommended in consideration of strengths, condition of surface and balance between cost and performance.

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Physical and chemical Cross-Linking Effects in Thermoplastic Polyurethane Elastomers with Different Macroglycol

  • Heo, Jae-Ho;Jeong, Du-Gam;Kim, Eun-Young;Kim, Han-Do
    • Proceedings of the Korean Fiber Society Conference
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    • pp.126-130
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    • 1997
  • A series of Thermoplastic polyurethane elastomers was prepared via a two-step polymerization process. The NCO/OH feed ratio of polyurethane synthesized in this study was varied from 1 to 1.3. Studies have been made on the effects of chemical and physical cross-linkina, and the properties of thermoplastic polyurethane elastomers based on isophorone diisocyanate (IPDI)/1,4-butanediol (BD)/poly(propylene glycol) (PPG, MW:2000), isophorone diisocyanate (IPDI)/BD /poly(oxytetramethylene) glycol (PTMG, MW:2000) was compared. These materials were characterized using FTIR spectrometer, dynamic mechanical thermal analyzer, and tensile retraction tester. PTMG based polyurethane elastomers showed higher elasomeric behavior than PPG based polyurethane elastomers at the same NCO/OH ratio. This feature has been connected with the specific nature of the polyols. The permanent set(%) was decreased with increasing maximum elongation from 50% to 300%.

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Preparation of Temperature-sensitive Polyurethane Membrane and Its Permeation Characteristics (온도감응성 Polyurethane 막의 제조 및 투과특성)

  • 김진홍;이영무
    • Membrane Journal
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    • v.6 no.4
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    • pp.236-241
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    • 1996
  • We prepared temperature-sensitive polyurethane and its water permeation characteristics for possible uses as drug delivery systems. Mechanical properties and Tg of polyurethane depend on the molecular weight of polyol and the amount of hard segment. We confirmed the increase of permeability with temperature. This fact indicates the future use of the present material in drug delivery systems.

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Computer Model for Fibrinogen Adsorption on Polyurethane Surface

  • Kim, Jong-Won;Shin, In-Sun;Ryu, Gyu-Ha;Lee, Kyu-Back;Han, Dong-Keun;Kim, Young-Ha;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
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    • v.15 no.1
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    • pp.51-56
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    • 1994
  • Protein adsorption on the polyurethane surface was modelled by a modified random sequential adsorption(RSA) process. In this model, polyurethane surface was modelled as a mixed domain of hydrophobic and hydrophilic parts which was implemented by a 2 dimensional $150{\times}150$ lattice in the computer. Protein adsorption was simulated using a small box which represents a particle of the protein, and polyurethane lattice by considering their hydrophobic interaction. In order to validate the model, we perfonned fibrinogen adsorption on polyurethane surface. Isotherms of the adsorbed protein were calculated and compared to the experimental data. The protein adsorption on the polyurethane surface could be well described using this computer model.

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Effect of high molecular weight isocyanate contents on manufacturing polyurethane foams for improved sound absorption coefficient

  • Sung, Giwook;Kim, Jung Hyeun
    • The Korean Journal of Chemical Engineering
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    • v.34 no.4
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    • pp.1222-1228
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    • 2017
  • Noises generated in automobile compartments can be controlled by utilizing sound absorption and insulation materials such as polyurethane foams. Polyurethane foams are synthesized by varying polymeric methylene diphenyl diisocyanate (MDI) content for exploring the effect of high functional isocyanate on cellular and acoustic properties. The use of polymeric MDI affects polyurethane matrix modulus and drainage flow rate of the foams, and it also has strong effects on cell structure and air flow resistance (AFR). The highest sound absorption coefficient is achieved at the optimum amount of the polymeric MDI. Therefore, the optimum amount of polymeric MDI content is recommended to achieve not only high sound absorption coefficient but also high transmission loss from the polyurethane foams.

A Study of Synthesis and Mechanical property measurement for Waterborne Acrylic Base coat Resin in Full-Grain Leather (Full-Grain 피혁용 수용성 아크릴 Base coat 수지의 합성 및 물성측정 연구)

  • Lee, Joo-Youb;Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.3
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    • pp.359-366
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    • 2011
  • In this study we experimented that how polyurethane effect to acrylic-polyurethane resin in Full-Grain leather coatings. First of all, we consummated waterborne acrylic emulsion and waterborne polyurethane resin, Than we prepared F.G leathers which were coated by acrylic resin and acrylic-polyurethane resins. According to measured data for solvent resistance, acrylic resin and acrylic-polyurethane resins had good property. Sample a(WAC) had most low strength($2.10kg_f/mm^2$) and sample d(WAC 93 : WPU 7) had most high strength($3.41kg_f/mm^2$). Also we knew that most good property of abrasion is d(47.4 mg). In elongation case, a(WAC) had most good result(645 %) in this experiment.

Evaluation of Smoke Density and Noxious Gas for Phenol Foam Insulation (페놀 폼 단열재의 연기밀도 및 가스유해성 평가)

  • Park, Hyung-Ju
    • Journal of the Korean Society of Safety
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    • v.25 no.1
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    • pp.38-43
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    • 2010
  • The smoke density and noxious gas for phenol foam and polyurethane foam were measured according to test methods in ASTM E 662 and KS F 2271. It was observed that phenol foam had the possibility of application for sandwich panel and board compared with polyurethane foam. In the experimental results, phenol foam showed comparatively excellent property than polyurethane foam in smoke density and noxious gas. The polyurethane foam showed comparatively high smoke density and didn't meet the evaluation standard of noxious gas in KS F 2271. From the experimental results of smoke density and noxious gas, it can be said that phenol foam has both comparatively good safety and high possibility of application than polyurethane foam in the building fire of sandwich panel structure because of lower smoke density and noxious gas.

Study for Binary Liquid Type Fire Retardant White Paint of Polyurethane Lacquer (저연기성 이액형 방염우레탄락카 백색도료 연구)

  • Kwon, Kyungok
    • Applied Chemistry for Engineering
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    • v.18 no.5
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    • pp.527-530
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    • 2007
  • The binary liquid type fire retardant paint of polyurethane (alkyd resin) lacquer is developed to cover the defect of one liquid type white paint of chlorinated rubber used generally but which has weak surface and poor adhesive strength to the wood as well as generating much black smoke when it is firing. The properties of the composition of binary liquid type of white paint of polyurethane lacquer developed in this study for using to wood has shown that the better suppressed smoke generation and enhanced the adhesive strength to the wood than that of fire retardant white paint used.