• Title, Summary, Keyword: polyurethane

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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.

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

  • Sung, Giwook;Kim, Jung Hyeun
    • 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.

Preparation and Properties of Aniline Terminated Waterborne Polyurethane/Multi-walled Carbon Nanotube Composite Coating Solutions (Aniline Terminated Waterborne Polyurethane/Multi-walled Carbon Nanotube 복합 코팅 용액의 제조 및 물성)

  • Hong, Min Gi;Kim, Byung Suk;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.50 no.3
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    • pp.403-409
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    • 2012
  • Polyurethane prepolymers were prepared from poly (carbonate diol), isophrone diisocyanate, and dimethylol propionic acid. Then, aniline terminated waterborne polyurethane dispersion (ATWPUD) was synthesized by capping aniline on the NCO group of the prepolymer. Subsequently, ATWPUD was mixed with multi-walled carbon nanotube (MWCNT) to yield coating solutions, and the mixture was coated on the polycarbonate substrate. The surface resistance ($10^{7.6}{\sim}10^{7.7}{\Omega}/cm^2$) of coating films from ATWPUD showed better conducting properties than that ($10^{10.9}{\Omega}/cm^2$) from pure waterborne polyurethane dispersion (WPUD) when MWCNT was mixed. Also, the surface resistance of coating films was increased, but the pencil hardness and adhesion were decreased with increasing the amount of MWCNT added in the ATWPUD.

A Study on the Handle of Cotton Fabric treated with Chitosan Polyurethane Mixed Solution by KES (I) (키토산-폴리우레탄 혼합용액(混合溶液)으로 처리(處理)된 면직물(綿織物)의 KES에 의한 태분석(態分析) (I))

  • Yoon, Se-Hee;Jeon, Dong-Won;Kim, Jong-Jun
    • Journal of Fashion Business
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    • v.8 no.1
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    • pp.141-155
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    • 2004
  • Chitosan, the natural biodegradable polymer derived from chitin by de- acetylation, has been widely applied to the textile finishing processes for excellent anti-microbial characteristic and handle improvement of fabric. The purpose of this study is to investigate the change of handle when cotton fabric is treated with chitosan-polyurethane mixed solution. The viscosity values of chitosan solutions were 8cps and 50cps, and the wet-pick-up% was maintained at 90%. In case of mixing with water soluble polyurethane, the mixture ratio of chitosan and polyurethane was settled on the solid content ratio of 1:0, 1:0.5, 1:1, 1:2. Also the change of physical properties by neutralization in NaOH solution was studied. The results can be summarized up as follows : 1. Extensibility(EM) and tensile energy(WT) of cotton fabric treated with chitosan are decreased, but bending rigidity(B) is remarkably increased. With the addition of polyurethane, the decrease of EM and WT is weakened and the increase of B is weakened. The case of neutralization is similar to the case of polyurethane addition. 2. By treating fabric with chitosan, FUKURAMI(Fullness and softness) is decreased, but KOSHI(Stiffness), SHARI(Crispness), HARI(Anti-drape Stiff ness) are increased. With the addition of polyurethane, the decrease of FUKURAMI is diminished and the increase of KOSHI, SHARI, HARI are diminished. 3. As the viscosity of chitosan solution increased, the air permeability value increased. The addition of polyurethane decreased the air permeability.

Synthesis and Characteristics of Cationic Polyurethane-Acrylates as a Retention Aid (양이온성 폴리우레탄-아크릴레이트계 보류향상제의 합성 및 특성)

  • Han, Chul;Kim, Doo-Won;Yoon, Doo-Soo;Kim, Sun;Hong, Wan-Hae;Kim, Jung-Gyu
    • Elastomers and Composites
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    • v.39 no.3
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    • pp.209-216
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    • 2004
  • Two types of polyurethane-acrylate polymer were synthesized by reaction of 2-hydroxyethyl methacrylate(HEMA), acrylamide(AA), and polyurethane prepolymer. Water-soluble cationic polyurethane/acrylate retention aids were prepared by using polyurethane-acrylate, benzyl chloride and distilled water. The retention, drainage and strength properties of the retention aids were investigated. The retention of cationic polyurethane/acrylate type retention aids maintained around 70 % regardless of nm. COD value of white water was much reduced by adding the retention aids to it. Drainage property was also improved by addition of the retention aids. In addition, specific compression strength of the paper was improved a little by addition of the retention aids. PU-HEMA type showed better performance than PU-AA in terms of compression strength of the paper.

Study on Thermal and Physical Properties of One-component Curable Hybrid Polyurethane Elastomer (1액 경화형 하이브리드 폴리우레탄 탄성체의 열적, 물리적 특성에 관한 연구)

  • Mok, Dong Youb;Kim, In-Soo;Kim, Dong Ho;Kim, Gu Ni
    • Elastomers and Composites
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    • v.47 no.4
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    • pp.318-328
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    • 2012
  • In this study, the one-component curable polyurethane resin was manufactured using blocked isocyanate and hybrid technology. To prepare the one-component curable hybrid polyurethane, silica hybrids including hydroxyl group was synthesized, and the size, shape and distribution of hybrid particle in polyurethane resin were confirmed. Then the dissociation property, mechanical property and molding property of blocked isocyanate were investigated. The dissociation property of blocked isocyanate in one-component curable polyurethane became better as the heating temperature and treatment time increased. The synthesized silica hybrid had spherical appearance and size of 23~27 nm in diameter, and it was observed that the hybrid particles were homogeneously distributed in polyurethane structure. In the case of hybrid polyurethane, the mechanical property, anti-abrasion and thermal property were higher than those of general polyurethane, and it was observed that the mechanical property was maintained when the plasticizer was introduced.

Studies on Recycling of Waste Polyurethane ( II ) (폐우레탄고무 재활용에 관한 연구 (II))

  • Lee, Hyung-Kyu;Hwang, Sung-Hyuk;Kim, Jin-Kuk
    • Elastomers and Composites
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    • v.35 no.3
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    • pp.227-235
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    • 2000
  • This study focused on the recycling technology and application of waste polyurethane scrap($5{\sim}7mm$) and waste urethane form from the footware scrap. Firstly we suggest the waste polyurethane can be used as a component of medium for hydroponic rose culture. Secondly, recycled thermoplastic polyurethane(RTPU) was produced and blended it with high impact polystyrene(HIPS). And also, in order to extend application of recycling field, the former was produced with adding the amine foaming agent to RTPU/HIPS alloy. The main purpose of this study is to diverse of the recycling of the waste polyurethane.

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Synthesis of Novel Hydroxy-terminated Polyether for Solid Propellent Polyurethane Binder (고체 추진제용 폴리우레탄 바인더를 위한 새로운 폴리에테르 공중합체 디올(HTPE)의 합성)

  • Shin, Bum-Sik;Lee, Bum-Jae;You, Ho-Joon;Park, Young-Chul
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.221-226
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    • 2008
  • Novel synthetic routes were proposed for hydroxy-terminated Poly(EO-co-THF) by Cationic ring-opening copolymerization of Tetrahydrofuran(THF) and Ethylene oxide(EO). It was carried out using Boron trfluoride tetrahydrofuranate($BF_3$ THF complex) as catalyst in the presence of 1,4-butandiol. The resultant products are well-defined linear polyetherpolyol. Polyurethane(TPU) were prepared using resultant polyetherpolyol with IPDI/N-100 as curing agent and TPB(Triphenylbismuth) /MA(Maleic anhydride) mixture as cure catalyst. Mechanical properties of TPU prepared from poly(EO-co-THF) polyol were investigated and compared with polyurethane using ATK HTPE.

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Synthesis of Glycidyl Azido Copolyetherdiol for Solid Propellant Polyurethane Binder (Glycidyl Azido Copolyetherdiol을 이용한 Polyurethane의 합성과 특성분석)

  • Shin, Bum-Sik;Lee, Bum-Jae;Park, Young-Chul;Hwang, Kab-Sung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.231-236
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    • 2008
  • The well-defined copolymers derived from Epichlorohydrin(ECH), Tetrahydrofuran(THF) were synthesized by Cationic ring-opening polymerization(CROP) with 1,4-Butandiol, a initiator, and $BF_3THF$ Complex, a catalyst via Activated monomer mechanism, which could lead to hydroxyl-terminated polyethers. The molecular weight of polymers were dependant on the ratio of [monomer]/[diol], Copolymer structures were controlled by monomers feed ratio, ECH and THF added. This polymers were functionalized from Chlorine group to Azide group using $S_N2$ reaction. Synthesized polymers were found to be as the prepolymer for polyurethane. Polyurethane was synthesized in the presence of N-100/IPDI mixture, a curing agent, and TPB(triphenyl bismuth)/MA(Maleic anhydride) mixture, a catalyst system. The curing behavior and mechanical properties of polyurethane after mixing with various prepolymer’s composition and the molecular weight were studied.

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A Study on Characteristics of Urethane Polymer as Injection Material for Ground Improvement

  • Chun, Byung-Sik;Park, Heung-Kyu;Ryu, Dong-Sung
    • Geotechnical Engineering
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    • v.12 no.3
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    • pp.99-108
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    • 1996
  • The physical and chemical properties of polyurethane-yieding twofomponent liquid injection mixture and those of the resulting polyurethane solid foam for chemical grouting are investigated. The chemical experiments on the factors influencing the properties of polyurethane show that the behaviors of polyurethane-yielding liquid material and those of the produced polyurethane solid foam are greatly affected by the ground conditions such as temperature, water content and density of soil. The ground reinforcing and water -blocking effects of polyurethane grouting are examined through field case history of tunnel ericavati on of the subway under construction.

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