• Title/Summary/Keyword: isocyanate

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Fabrication of Silica-Containing Breathable Waterproof Polyurethane Dispersion Film (Silica를 함유하는 Polyurethane dispersion 투습방수 Film의 제조)

  • Shin, Hyun-Ki;Huh, Man-Woo;Yoon, Nam-Sik
    • Textile Coloration and Finishing
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    • v.27 no.2
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    • pp.126-131
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    • 2015
  • Silica-polyurethane hybrid breathable films were prepared and their breathabilities were assessed. Appropriately aggregated silica was prepared through sol-gel reaction of water glass and its particle size ranged 360~500nm. The polyurethane dispersion was prepared by the reaction of isophorone diisocyanate(IPDI) as diisocyanate and polytetramethylene glycol(PTMG) and dimethylol propionic acid(DMPA) as polyol, particle size ranging 30~120nm. The reaction between isocyanate and hydroxyl group to form urethane bonding was checked by the intensity of the stretch peak of isocyanate at $2270cm^{-1}$ in the FT-IR. The silica was incorporated into polyurethane dispersion and casted into film. It was shown that the incorporated silica(1~5wt.%) increased water vapour permeability of the films by 30~100%, and decreased the hydrostatic pressure by 10~40%. From the results, it could be concluded that the appropriate hybridization of silica can increase the breathability of polyurethane dispersion film, while minimizing the loss of hydrostatic pressure.

Induction of Single Helical Screw Sense in Poly (n-Hexyl Isocyanate) by End-capping with a Chiral Moiety

  • Nath G. Yogendra;Samal Shashadhar;Park, Sang-Yoon;Murthy C.N.;Lee, Jae-Suk
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.334-334
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    • 2006
  • Helical polymers like polyisocyanates with single screw sense are essential to exhibit sophisticated functions like molecular recognition, self-replication, chirality memory and catalytic activity. One approach that has not been explored is the effect on handedness of the polyisocyanates through end-capping with a chiral residue. Induction of chirality in poly(n-hexyl isocyanate) was studied by end-capping with chiral (R and S) 2-bromo-3-methylbutyryl chloride(R-BMBC and S-BMBC). We have shown that a control over living anionic polymerization of HIC by using a suitable initiator affords an opportunity to introduce chiral end-groups with 100% yield and in high purity. This has resulted in helicity induction through extended lengths several orders of magnitude.

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Study on the Novel Materials Containing Nanoparticles and Isocyanate Group for Strength Improvement of Hydrogel Ophthalmic Lens

  • Lee, Min-Jae;Sung, A-Young
    • Journal of Integrative Natural Science
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    • v.11 no.2
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    • pp.113-120
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    • 2018
  • This study was planned to prepare the high strength hydrogel ophthalmic lens containing isocyanate group and nanoparticles. HDI with carbon nanoparticles were used as additives for the basic combination of HEMA, MA and MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The mixture was heated at $100^{\circ}C$ for an hour to produce the high performance hydrogel ophthalmic lens by cast mold method. Measurement of the physical characteristics of the produced material showed that the refractive index was in the range of 1.4027~1.4600, water content 25.21~44.01%, contact angle $54.18{\sim}72.94^{\circ}$, visible light transmittance 53.03~92.09%, and tensile strength 0.1024~0.2359 kgf and breaking strength was 0.0872~0.2825 kgf. The results showed an increase of refractive index while the decrease in water content. And also, the breaking strength was highest when the addition ratio of HDI was 5%(wt). As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained.

Physical Properties and Flame Retardancy of PU Coatings Polymerized with Two Different Types of Isocyanates and Dichloro-Polyester Polyol (두 종류의 이소시아네이트와 디클로로-폴리에스테르 폴리올로부터 중합한 PU 난연도료의 도막물성 및 난연성)

  • 양인모;김성래;박형진;함현식;우종표
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.193-199
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    • 2002
  • The dichloro-polyester polyol (DCBAO) which was synthesized in our earlier work was cured at room temperature with two different type of curing agents including Desmodur N-3300 and Desmodur L-75 to get a polyurethane flame-retardant coatings (DCBAO/N-3300=DEBAN and DCBAO/L-75=DCBAL). We could not observe any deterioration of physical properties of the flame-retardant PU coatings (UCBAN and DCBAL) in comparison with the conventional PU coatings. Thermal resistance of DCBAL-type flame-retardant coatings, which was measured by yellowness index difference, was inferior to that of DCBAL-type PU coatings. We believe that this phenomena is attributed to the poor thermal resistance of Desmodur L-75 isocyanate. It was observed that the LOI values were 25∼26% for the PU coatings containing 20∼30 wt% of 2,4-dichlorobenzoic acid.

Curing Reaction and Physical Properties of High-Solid Acrylic/Isocyanate Coatings (하이솔리드 아크릴/이소시아네이트 도료의 경화반응과 도막물성)

  • Park, Hong-Soo;Shim, Il-Woo;Jo, Hye-Jin;Kim, Seong-Kil;Kim, Myung-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.4
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    • pp.371-378
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    • 2005
  • In the previous study, three kinds of monomers and the functional monomer, acetoacetoxyethyl methacrylate (AAEM), which could improve the film property and cross-linkage, were polymerzied into acrylic resin copolymers (HSA-98-20, HSA-98-0, HSA-98+20) containing 80% solid content. In this study, the high-solid coatings(HSA-98-20C, HSA-98-0C, HSA-98+20C) were prepared by the curing reaction between acrylic resins containing 80% solid content and isocyanate at room temperature. Various properties were examined for the film coated with the prepared high-solid coatings. The introduction of AAEM in the coatings enhanced the abrasion resistance and solvent resistance of coatings, which indicated the possible use of high-solid coatings for top-coating materials of automobile. The curing times measured by viscoelastic measurement were 350, 264, and 212 min for HSA-98-20C, HSA-98-0C, and HSA-98+20C, respectively. This shows that the curing times become shorter with increasing $T_g$ values.

Analysis of impingement mixing for coating in injection mold (사출금형 안에서 코팅을 위한 충돌혼합에 관한 해석)

  • Kim, Seul-Woo;Lee, Ho-Sang
    • Design & Manufacturing
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    • v.13 no.4
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    • pp.1-9
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    • 2019
  • In-mold Coating is a method that can simultaneously perform injection molding and surface coating in injection mold. The material used for coating is two-component polyurethane which is composed of polyol and isocyanate. L-type mixing head can be used to mix polyol and isocyanate uniformly, and inject them inside the mold cavity. The surface quality of the injection molded products by using in-mold coating depends on the mixing uniformity between main agent and hardener. In this study, flow analysis was performed to design a mixing head for uniform mixing of two-component polyurethane. Especially the effects of design parameters of mixing head on mixing uniformity and nozzle pressure were investigated. The parameters of mixing head were mixing chamber diameter, cleaning cylinder diameter, nozzle alignment angle in the horizontal and vertical direction, and cleaning piston position. It was found that optimal design values were mixing chamber diameter of 3.5 mm, cleaning cylinder diameter of 5.0 mm, nozzle horizontal/vertical alignment angles of 140°/160°, and cleaning piston position of 1.8 mm. The optimal values would be used to develop a two-component mixing head achieving an uniform mixing for in-mold coating.

Mechanical and Physical Properties of Roof Tile Prepared from Sugar Cane Fiber

  • Wong on, Jessada;Surin, Prayoon;Apawet, Chaiyaprek;Eidhed, Krittee;montra, Sunate;Aumkongthum, Kaichai;Thumsorn, Supaphorn
    • International Journal of Advanced Culture Technology
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    • v.3 no.1
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    • pp.86-89
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    • 2015
  • Sugar cane, renewable fiber resources, were used for roof tile production. Urea formaldehyde, phenol formaldehyde and isocyanate resin were used as binders in this study. Roof tile specimens with 400 mm wide, 400 mm long and 5 mm thick were prepared by compression molding. Physical and mechanical properties of the specimens were analyzed by water absorption, thickness swelling, thermal conductivity, density, modulus of rupture and modulus of elasticity. From the results, water absorption at 1 and 24 hours was 19-47 % and 38-57 %, respectively. Thickness swell at 24 hours was 15-29%. Thermal conductivity was 0.016, 0.017 and 0.019 W/m.K when using isocyanate, urea formaldehyde and phenol formaldehyde, respectively. Density of the specimens was 770-860 kg/m3. Modulus of rapture was 255-280 MPa. Modulus of elasticity was 5.1-7.6 GPa. Physical and mechanical properties of the specimens indicated that they would be applied for roof tile and construction.

Preparation and Characterization of Polyurethane Bioadhesive from Hydroxyl-terminated Polylactide and Imidazole-blocked Isocyanate (말단 수산화기를 가진 폴리락타이드와 이미다졸로 블록된 이소시아네이트를 이용한 폴리우레탄 바이오접착제의 합성 및 물성 평가)

  • Shen, Tengfei;Sun, Yingjuan;Sun, Chunfeng;Lu, Mangeng
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.232-239
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    • 2013
  • A series of novel imidazole-blocked diisocyanate bioadhesives (IBAs) were synthesized from reaction of toluene 2, 4-diisocyanate (TDI), isophorone diisocyanate (IPDI), hydroxyl-terminated polylactide (HO-PLA-OH), 1,1,1-trimethylolpropane (TMP), and imidazole. Synthesis of IBAs was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) revealed that the TDI-based IBA had lower thermal dissociation temperature and a faster deblocking rate than IBA based on IPDI. Hydroxyl-terminated polyurethane (HPU) was introduced to study the adhesive effect of the synthesized IBAs. Improvement on elastic modulus, tensile strength and water resistance of IBA-modified HPU in comparison with neat HPU suggested the good adhesive effect of IBA due to the strong chemical reaction between released NCO groups from IBA and hydroxyl groups from HPU.

Thermal Decomposition Behavior of Blocked Diisocyanates Derived from Mixture of Blocking Agents

  • Lee Jung Min;Subramani Sankaraiah;Lee Young Soo;Kim Jung Hyun
    • Macromolecular Research
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    • v.13 no.5
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    • pp.427-434
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    • 2005
  • To improve the performance and reduce raw material costs, blocked isocyanates were prepared with mixture of blocking agents in many industries. Three blocked isocyanates (adducts) namely $\varepsilon$-caprolactam/benzotriazole-blocked 4,4'-diphenylmethane diisocyanate (MDI), toluene-2,4-diisocyanate (TDI) and 4,4'-dicyclohexyl-methane diisocyanate ($H_{12}$MDI) were synthesized. Six reference adducts were also prepared by blocking MDI, TDI, and $H_{12}$MDI with $\varepsilon$-caprolactam ($\varepsilon$-CL) or benzotriazole. The reactions were carried out in acetone medium and dibutyltin dilaurate (DBTDL) was used as a catalyst. The progress of the blocking reaction was monitored by IR spectroscopy. De-blocking temperatures (dissociation temperatures) of these adducts were studied using DSC and TGA and the results were correlated. As expected, the thermal analysis data showed that de-blocking temperature of blocked aromatic isocyanates was lower than that of the blocked aliphatic isocyanates. The low de-blocking temperature of blocked aromatic isocyanate could be due to electron withdrawing benzene ring present in the blocked isocyanates. It was also found that benzotriazole-blocked adducts de-blocked at higher temperature compared with $\varepsilon$-CL-blocked adducts.

Study on Adhesion and Mechanical Properties of Adhesive Resin Using Microcapsule with Isocyanate Compound (이소시아네이트를 포함하는 Microcapsule을 사용한 접착수지의 특성에 관한 연구)

  • Kim, Dong Ho;Kim, Gu Ni
    • Journal of Adhesion and Interface
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    • v.15 no.3
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    • pp.109-115
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    • 2014
  • In this study, we synthesized and identified microcapsule containing isocyanate, and investigated the mechanical and adhesion properties of polyurethane resin by adding microcapsule. We found out that the core material of microcapsule and the component weight fraction of microcapsule from the FT-IR and TGA analysis. From the results of adhesion and mechanical property tests, we confirmed that in case of using microcapsule for adhesive resin composition, adhesion strength, tensile strength and abrasion were improved by cross-linking reaction between urethane and IPDI in microcapsule.