• Title/Summary/Keyword: Polyurethanes

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Preparation and Properties of Waterborne Polyurethanes and Their Blend Films (수분산 폴리우레탄과 그의 블렌드물의 제조 및 물성)

  • Yoo, Byung-Ha;Kim, Eun-Young;Kim, Han-Do
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.38-41
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    • 2003
  • Recently, Waterhorne polyurethane(WBPU) have been used for a wide range of commercial applications due to the increasing environmental regulation to reduce low-volatile organic compounds in coating and adhesives materials [1-8]. The WBPU was used in coating industry on fiber at first, and its market is increasing these days. Especially, the Waterborne polyurethane film even is widely used in the field of breathable coating fiber or medical science [9-10]. Water vapor permeability(WVP) is the key property for application to breathable coating fiber. (omitted)

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A Study on the Synthesis and Characterization of Waterborne Polyurethanes for Water Vapor Permeable / Waterproof - Effect of PEG and DMPA Content (투습방수용 수분산 폴리우레탄의 합성 및 특성에 관한 연구 - PEG와 DMPA 함량의 영향 -)

  • Kwak, Yong-Sil;Kim, Eun-Young;Kim, Han-Do
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.42-45
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    • 2003
  • Polyurethane(PU) products are generally used in the automobile, paint, furniture, adhesive, the medical and textile industries. Recently, the increasing acceptance of waterborne polyurethane (WBPU) Is motivated by more stringent environmental requirements, such as the reduction of solvent emissions into the atmosphere [1]. The application for textiles includes suede processing, soft-hand processing, wrinkle-free processing, antistatic processing, sizing and adhesives. (omitted)

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Synthesis of Novel Silicone Containing Vinylic Monomer and Its Uses in the Waterborne Polyurethane-Veova/Vinyl Acetate Hybrid Emulsion Copolymers (비닐단량체를 함유한 새로운 실리콘의 합성과 수성 Polyurethane-Veova/Vinyl Acetate 하이브리드 에멀젼 공중합체 내에서 사용)

  • Naghash, Hamid Javaherian;Naeni, Elham Kasaeian
    • Polymer(Korea)
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    • v.35 no.5
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    • pp.409-418
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    • 2011
  • A novel silicone (Si) containing vinylic monomer, N-(3-(triethoxysilyl)propyl) methacrylamide (TESPMA), based on 3-aminopropyltriethoxysilane (APTES) and methacryloyl chloride (MCl) has been synthesized for formulation of waterborne polyurethane (WPU). Two types of vinyl group containing Si, methacryloxypropyltriethoxysilane (MPTES) and triethoxyvinylsilane (TEVS), have been used as coupling reagents for comparison of the effects of Si kinds with TESPMA on the WPU. A series of new siliconized WPU, vinyl acetate/vinyl ester of versatic acid (VAc-Veova), TESPMA, MPTES and TEVS hybrid latexes have been successfully prepared by emulsion polymerization in the presence of WPU dispersion.

Properties of Blood Compatible Crosslinked Blends of $Pellethene^{(R)}$/Multiblock Polyurethanes Containing Phospholipid Moiety/C-18 Alkyl Chain

  • Yoo, Hye-Jin;Kim, Han-Do
    • Macromolecular Research
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    • v.16 no.7
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    • pp.596-603
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    • 2008
  • To improve the mechanical properties, dimensional stability and blood compatibility, the biomedical material $Pellethene^{(R)}$ was blended with multiblock polyurethane (MPU) containing phospopholipid/long alkyl chain (C-18) at the various MPU contents and crosslinked using dicumyl peroxide as a crosslinking agent. The maximum MPU content for stable $Pellethene^{(R)}$/MPU blended films was approximately 30 wt%. The optimum crosslinking agent content and crosslinking time with respect to the mechanical properties were 4 wt% and 3 h, respectively. The mechanical properties (tensile strength and elongation at break) and water absorption of the crosslinked blend film increased with increasing MPU content. The test of platelet adhesion on the surfaces of the crosslinked blend film showed a decrease in the level of platelet adhesion from 70% to 6% with increasing MPU content from 0 to 30 wt%. These results suggest that the crosslinked $Pellethene^{(R)}$/MPU-30 (MPU content: 30 wt%) sample has strong potential as a novel material for blood compatible material applications.

Mechanical Behavior of Shape Memory Fibers Spun from Nanoclay-Tethered Polyurethanes

  • Hong, Seok-Jin;Yu, Woong-Ryeol;Youk, Ji-Ho
    • Macromolecular Research
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    • v.16 no.7
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    • pp.644-650
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    • 2008
  • This study examined the effect of nanoclays on the shape memory behavior of polyurethane (PU) in fibrous form. A cation was introduced into the PU molecules to disperse the organo-nanoclay (MMT) into poly($\varepsilon$-caprolactone) (PCL)-based PU (PCL-PU). The MMT/PCL-PU nanocomposites were then spun into fibers through melt-processing. The shape memory performance of the spun fibers was examined using a variety of thermo-mechanical tests including a new method to determine the transition temperature of shape memory polymers. The MMTs showed an improved the fixity strain rate of the MMT /PCL- PU fibers but a slight decrease in their recovery strain rate. This was explained by the limited movement of PU molecules due to the presence of nanoclays. The shape memory performance of the MMT/PCL-PU fibers was not enhanced significantly by the nanoclays. However, their recovery power was improved significantly up to a strain of approximately 50%.

The Effect of Improved Crosslink Density on the Properties of Waterborne Polyurethanes Using Sol-Gel Process (졸-겔 법을 통한 수분산형 폴리우레탄 합성 및 가교밀도 개선에 따른 성능 연구)

  • Kim, Young Ryul;Park, Jin Hwan
    • Corrosion Science and Technology
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    • v.15 no.6
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    • pp.297-302
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    • 2016
  • Water-based systems are dominating the coating market because of worldwide VOCs regulations. Research is focusing especially on waterborne polyurethane (WPU) because of its unique mechanical and chemical properties. However, commercial WPU consists of linear thermoplastic polymers with polar groups on the main chain, which do not perform as well as solvent-borne PU in a two-pack system. In this study, APTES were used as a chain crosslink agent to overcome commercial WPU's limited performance. WPUs synthesized by using a sol-gel process were evaluated with FT-IR, particle analysis, TGA, tensile tests, pull-off tests, SEM, and EIS. The results showed that WPUs with added APTES had better thermal stability, mechanical properties, and water resistance than did WPUs without added APTES. Consequently, the sol-gel process increased the crosslink density of WPUs and modified the WPU's own properties.

Synthesis of Biomass-derived Polyurethane by Chain Extender Type

  • Sohn, Mi Hyun;Li, Xiang Xu;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.54 no.4
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    • pp.279-285
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    • 2019
  • Bio-based polyester polyols were synthesized using esterification with azelaic acid, sebacic acid, and 1,3-propanediol. Polyurethanes were prepared using chain extenders (1,4-Butanediol, 1,3-Propanediol, and isosorbide) and 4,4'-diphenylmethane diisocyanate with a mixing ratio of 1:1:1.1. Subsequently, the properties of the polymers prepared using the different chain extenders were compared. The synthesis of polyurethane was confirmed by FT-IR, TGA, and GPC. The mechanical properties (hardness, ball rebound, and tensile strength) of the materials were analyzed using shore A tester, taber abrasion, and UTM. heat, chemical, and water resistances of the prepared materials were measured by comparing the tensile strengths according to external changes.

Synthesis and Characteristics of 2 Step-curable Shape Memory Polyurethane (2단계 경화형 형상기억 폴리우레탄의 합성 및 분석)

  • Noh, Geon Ho;Lee, Seungjae;Bae, Seong-Guk;Jang, Seong-Ho;Lee, Won-Ki
    • Journal of Environmental Science International
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    • v.27 no.11
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    • pp.1023-1028
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    • 2018
  • Shape memory materials are widely used in high-tech industries. Although shape memory polymers have been developed, they have a disadvantage, only unidirectional resilience. Shape memory polymers with bi-directional recovery resilience have been actively studied. In this study, a bidirectional shape memory polyurethane was synthesized using poly(${\varepsilon}$-caprolactone) diol, methylene dicyclohexyl diisocyanate, and hydroxyethyl acrylate. The first physical curing occurred between hard segments and hydrogen bondings when the solution was dried. The second curing in acrylate groups was performed by UV exposure. A degree of curing was analyzed by infrared spectroscopy. The shape memory properties of 2 step-cured polyurethanes were investigated as a function of UV curing time.

Synthesis of Fluorine Modified Polyurethane and Surface Modification (불소 변성 폴리우레탄의 합성과 표면 개질)

  • Lim, Chul Hwan;Choi, Hee Sung;Noh, Si Tae
    • Applied Chemistry for Engineering
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    • v.10 no.6
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    • pp.913-916
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    • 1999
  • Fluorine modified diisocyanate(FMD) was synthesized from tris(6-isocyanatohexyl)isocyanurate(TIHI) and N-ethyl-N-2-hydroxyethyl-perfluorooctanesulfonamide(HFA). Fluorine modified polyurethane(FMPU) was also synthesized from FMD and poly(tetramethylene) glycol(PTMG). Modified polyurethanes were made by blending FMPU into the polyester type base polyurethane(BPU). Surface and thermal properties of the blended BPU film was measured by contact angle measurement and DSC. As the amounts of FMPU was increased from 0 wt % to 1 wt %, the surface energy was dramatically decreased from 47.82 dyne/cm to 17.64 dyne/cm. But we observed little change of the contact angle with further increase in the amount of the FMPU up to 10 wt %. The data meant that the surface of the blended polyurethanes was hydrophobic due to the surface arrangement of the fluorine containing moiety in FMPU. Phase separation was induced by the incompatibility of FMPU and BPU for the samples having over 5 wt % of FMPU. The thermal analysis data of these samples showed the thermal behavior of the FMPU itself.

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