• Title, Summary, Keyword: polyurethane

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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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A Study on the Synthesis and Mechanical Characteristics of NATM Resin (HATM 수지의 합성 및 기계적 특성에 관한 연구)

  • Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.355-361
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    • 2005
  • The physical characteristics of polyurethane were examined by SEM, FT-IR tensile strength and mole % [NCO/OH]. Growing concerns in the environment-friendly architecture and public works have led to the development of solvent-free formulations that can be cured and foamed in air. Compared with general packing materials, this resin is much stronger in intensity and much longer in durability. Polyurethane foam resins were mainly composed of polyol, MDI, silicone surfactant, fillers, catalyst and blowing agent. The rigid foam of polyurethane in mechanical characteristics were due to chain extender and the increase of mole % [NCO/OH]. The change in the microstructure of polyurethane should be taken into account when considering the process of construction and durability through the polyurethane polymer resin in lots of industries.

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.

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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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.

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.

Recycling of Polyurethane Scraps (폴리우레탄 스크랩의 재활용)

  • Kim, Han-Na;Lee, Dai-Soo
    • Elastomers and Composites
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    • v.47 no.2
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    • pp.104-110
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    • 2012
  • Depending on the states of polyurethane scraps generated in the production sites of polyurethane or recycling center of polyurethane scraps, appropriate recycling technologies can be employed for the recycling of resources. In this study, recycling technologies for the polyurethane scraps were classified into physical recycling, chemical recycling, and energy recycling and reports in the literatures were discussed.

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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Numerical analysis on foam reaction injection molding of polyurethane, Part A: Considering re-condensation of physical foam agent

  • Han, HyukSu;Nam, Hyun Nam;Eun, Youngkee;Lee, Su Yeon;Nam, Jeongho;Ryu, Jeong Ho;Lee, Sung Yoon;Kim, Jungin
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.5
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    • pp.209-214
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    • 2016
  • Foam reaction injection molding (FRIM) is a widely used process for manufacturing polyurethane foam with complex shapes. Numerical model for polyurethane foam forming reaction during FRIM process has been intensively investigated by a number of researchers to precisely predict final shapes of polyurethane foams. In this study, we have identified a problem related with a previous theoretical model for polyurethane foam forming reaction. Thus, previous theoretical model was modified based on experimental and computational results.