• Title/Summary/Keyword: MDI

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A Study on the Stabilization of Monomeric MDI and Purification of Crude MDI (Crude MDI의 정제 및 Monomeric MDI의 안정화에 관한 연구)

  • Jung, Jong-Won;Kim, Young-Chul;Park, Nam-Cook
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.588-596
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    • 1996
  • The optimum conditions of the 1st and 2nd distillation had been investigated to obtaine a high quality monomeric MDI and fire reactive polymeric MDI by purification of crude MDI. Effect of additives on the monomeric MDI's color change, dimerization and the reactivity of polymeric MDI with standard polyol system has been tested. When the monomeric MDI yield is approximately 32%, 4,4'-MDI content is above 98% in the monomeric MDI at the 1st distillation. When the separation ratio of initial portion and residue percentage, reflux ratio are set at respectively, approximately 20wt%, 9wt%, above 2 in order to minimize the content of 2,4'-MDI in monomeric MDI, the freezing point of final distilled monomeric MDI is above $38.4^{\circ}C$. Since the monomeric MDI is inherently unstable in the room condition, monomeric MDI easily changes it's color and conducts self-polymerization reaction. To increase the stability of monomeric MDI, the composition of antioxidant, which is composed of phenolic 1st antioxidant, phosphorus 2nd antioxidant, UV absorbent and Hindered amine light stabilizer are used, and benzoyl chloride as antipolymerization agent test are that APHA color is less than 20, dimer content is remained less than 0.36wt% after 45 days storage of monomeric MDI.

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Thermal Stability of Phenylphosphonic Acid Modified Polyurethanes

  • Dong-Eun Kim;Seung-Ho Kang;Sang-Ho Lee
    • Elastomers and Composites
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    • v.58 no.2
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    • pp.70-80
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    • 2023
  • The effect of phenylphosphonic acid (PPOA) on polyurethane (PU) thermal stability was studied through Fourier transform infrared spectroscopy and Thermogravimetric analysis. To synthesize PPOA-modified PUs (PPOA-PUs), polyether-type diols (Mw=62, 106, 190, 419, 605) were chemically modified with PPOA and then reacted with 4,4'-dicyclohexylmethane diisocyanate (H12MDI) and 4,4-diphenylmethane diisocyanate (MDI). During thermal decomposition in air, the PPOA embedded in the PUs formed intumescent phosphocarbonaceous char. Below 400℃, PPOA-H12MDI-PUs were more unstable, as PPOA decomposed at lower temperatures than phenyl groups and aliphatic ethers. Above 550℃, the thermal stability of PUs followed this order: PPOA-MDI-PUs > PPOA-H12MDI-PUs > MDI-PUs > H12MDI-PUs. At 700℃, unmodified PUs had no residue, while the PPOA-MDI-PU residue was 4.4~23.0 wt.% and the PPOA-H12MDI-PU residue was 1.5~17.5 wt.%. The enhanced thermal stability of PPOA-MDI-PUs at high temperatures can be attributed to the synergetic effect of PPOA and phenyl groups on the formation of phosphocarbonaceous char.

Effect of pMDI as Coupling Agent on The Properties of Microfibrillated Cellulose-reinforced PBS Nanocomposite (pMDI 커플링제가 마이크로피브릴 셀룰로오스 강화 PBS 나노복합재료의 성질에 미치는 영향)

  • Jang, Jae-Hyuk;Lee, Seung-Hwan;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.4
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    • pp.483-490
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    • 2014
  • The effect of microfibrillated cellulose (MFC) content and coupling agent (polymeric methylene diphenyl diisocyanate, pMDI) on the properties of MFC-reinforced polybutylene succinate (PBS) nanocomposite. With increasing MFC content, tensile strength and elastic modulus were increased. More than 1.5 times in tensile strength of PBS/MFC(70/30) nanocomposite was improved by the addition of pMDI (1 phr), compared to the nanocomposite without pMDI. This trend was being significant in nanocomposite with higher MFC content. Thermal stability of the nanocomposite was increased by the addition of pMDI. These improvements is considered to be due to the improvement of MFC dispersion and interfacial adhesion between MFC and PBS matrix.

Multiplex Distribution Interface Analyzer Using Memory Sharing Techniqyes on Ethernet Mode for DRM/DRM+ Systems (DRM/DRM+ 이더넷모드의 다중화분산접속 설계분석)

  • Woo, Yongje;Kang, Mingoo;Seo, Jeongwook
    • Journal of Internet Computing and Services
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    • v.15 no.2
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    • pp.143-147
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    • 2014
  • In this paper, a novel MDI(Multiplex Distribution Interface) analyzer is designed in Ethernet-mode for DRM(Digital Radio Mondiale), and DRM+(Digital Radio Mondiale Plus) systems. The proposed MDI analyzer can reduce the overload of MDI packets by using memory sharing techniques into a common module block. In consequence, it verifies the received MDI packets by composition information of IP(Internet Protocol) and FAC(Fast Access Channel)/SDC(Service Description Channel) in DRM/DRM+ systems for the next generation digital radio broadcasting systems.

Bonding Strength of Ozonized Soybean Oil-based Modified pMDI Adhesive Hardened at High and Medium Temperature (오존산화 콩기름 변성 pMDI 접착제의 고온 및 중온 경화 접착력)

  • Lee, Eung-Su;Kang, Chan-Young;Park, Heon
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.6
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    • pp.541-546
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    • 2010
  • This study was to investigate the dry bond strengths of the plywoods manufactured with 3 hours ozonized soybean oil (SBO)/polymeric methylene diphenyl diisocyanate (pMDI) adhesive at mid and high curing temperature. In results of the dry bonding strengths of the 3 hrs-ozonized SBO mixed with pMDI at high curing temperature were respectively the strengths of weight ratio of 3hrs-ozonized SBO : pMDI, 1 : 0.5, 4.74 kgf/$cm^2$, 1 : 0.75, 7.14 kgf/$cm^2$ 1 : 1, 9.29 kgf/$cm^2$, 1 : 2, 16.53 kgf/$cm^2$, 1 : 3, 17.42 kgf/$cm^2$, and 1 : 4, 16.75 kgf/$cm^2$. Therefore, it was found that the equivalent ratio was formed approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. The dry bonding strengths of the 3hrs-ozonized SBO mixed with pMDI at medium curing temperature were respectively the strengths of weight ratio of 3 hrs-ozonized SBO : pMDI, 1 : 0.5, 3.16 kgf/$cm^2$, 1 : 0.75, 6.13 kgf/$cm^2$ 1 : 1, 8.18 kgf/$cm^2$, 1 : 2, 11.82 kgf/$cm^2$. In this experiment the higher bonding strength at high curing temperature was shown approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. If this wood adhesive is used at high curing temperature, it is possibile to bond the plywoods.

Performance of Hybrid Adhesives of Blocked-pMDI/Melamine-Urea-Formaldehyde Resins for the Surface Lamination on Plywood

  • Lubis, Muhammad Adly Rahandi;Park, Byung-Dae;Lee, Sang-Min
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.2
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    • pp.200-209
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    • 2019
  • To improve the water resistance of melamine-urea-formaldehyde (MUF) resins, different levels of blocked polymeric 4,4 diphenyl methane diisocyanate (B-pMDI) were blended with MUF resins to prepare B-pMDI/MUF hybrid adhesives, and their adhesion performances were evaluated for the surface lamination of fancy veneer on plywood. FT-IR spectra showed that the de-blocked -NCO groups reacted with the -OH of hydroxymethyl groups of the MUF resins to form urethane bonds at 2% B-pMDI/MUF, which was detected before and after their hydrolysis. The mass loss after the hydrolysis consistently decreased as the B-pMDI level increased, indicating an improvement in the water resistance. As the B-pMDI level increased, the activation energy of hybrid adhesives decreased, which improved the reactivity of the hybrid adhesives. Additionally, the water resistance improvement of the hybrid adhesives increased the tensile shear strength of the surface laminated plywood in semi-water proof and water-proof by 23 % and 8 %, respectively, at 2% B-pMDI level. This was likely due to the urethane linkages in the hybrid adhesives. However, the formaldehyde emission from plywood panels bonded with the hybrid adhesives increased in the dry state, indicating incomplete curing of the hybrid adhesives.

Effect of Several Exterior Adhesive Types on Dimensional Stability of Bamboo Oriented Particleboard

  • Iswanto, Apri Heri;Munthe, Rensus;Darwis, Atmawi;Azhar, Irawati;Susilowati, Arida;Prabuningrum, Dita Sari;Fatriasari, Widya
    • Korean Journal of Materials Research
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    • v.29 no.5
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    • pp.277-281
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    • 2019
  • The objective of this research is to evaluate the effect of adhesive types on dimensional stability of bamboo-oriented particleboard. The materials used in this research are bamboo tali(Gigantochloa apus J.A & J.H. Schult. Kurz), UF/MDI(8, 10, 12 % level), and MF, MDI, and PF at 7 % level. Particle and adhesive are mixed using a blending machine; then, mat forming and hot pressing processes are performed using adhesive-suitable temperature and time references. MDI resin is set at $160^{\circ}C$ temperature for 5 minutes. PF resin and MF resin are pressed at $170^{\circ}C$ for 10 minutes, and $140^{\circ}C$ for 10 minutes, respectively, while UF/MDI sets at temperature of $140^{\circ}C$ for 10 minutes. The results show that particleboard using PF resin produces the lowest thickness swelling value. The particleboard using UF/MDI resin also produces good response for thickness swelling value. Interesting things happen in that UF/MDI adhesive produces a thickness swelling value better than that of MDI resin. FTIR analysis on particleboard bonded by UF/MDI resin combination shows the presence of carbonyl group C=O vibration on multi substitution of urea at wave number of around $1,700cm^{-1}$.

Effect of Coupling Agent, Methylene Diisocyanate, in the Blending of Poly(methyl methacrylate)-Modified Starch and Styrene-Butadiene Rubber (폴리(메틸 메타크릴레이트)-개질된 전분과 스티렌-부타디엔 고무의 혼합에서 커플링제 메틸렌 디이소시아네이트의 효과)

  • Li, Mei-Chun;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.49 no.2
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    • pp.117-126
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    • 2014
  • Methylene diisocyanate (MDI) was investigated as a novel interfacial modifier to enhance the performances of poly(methyl methacrylate)-modified starch/styrene-butadiene rubber (PMMA-modified starch/SBR) composites. Owing to the formation urethane linkage on one side and ${\pi}-{\pi}$ adhesion on the other side, MDI acted as an intermediated linkage role in the PMMA-modified starch/SBR interfaces, which was evidenced by the morphological, mechanical, dynamic mechanical and thermal decomposition studies. As a result, the presence of MDI significantly improved the mechanical properties and thermal stability of PMMA-modified starch/SBR composites. In addition, the effect of starch concentration on the various performances of the resulted MDI/PMMA-modified starch/SBR composites, such as morphology, vulcanization characteristics, mechanical properties, toluene swelling behavior, and thermal stability were investigated and discussed in detail. The obtained MDI/PMMA-modified starch/SBR composites exhibited superior mechanical properties to carbon black/SBR (CB/SBR) composites, demonstrating the potential use of the renewable starch as a substitute for CB in the rubber compounds.

Characteristics of Low Density Fiberboards for Insulation Material with Different Adhesives (I) - Thermal Insulation Performance and Physical Properties - (다양한 접착제로 제조한 단열재용 저밀도섬유판의 특성(I) - 단열성능 및 물리적 성질 -)

  • Jang, Jae-Hyuk;Lee, Min;Kang, Eun-Chang;Lee, Sang-Min
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.3
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    • pp.360-367
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    • 2017
  • This study was carried out to compare the characteristics of low density fiberboards (LDFs) manufactured with different adhesive types such as melamine urea formaldehyde (MUF), phenol formalehyde (PF), emulsified MDI (eMDI) and latexes resins. As results, hard LDFs were successfully manufactured by MUF, PF and eMDI resins. Thermal conductivities of all LDFs were significantly lower than commercial medium density fiberboard. Especially, all LDFs showed comparable thermal insulation performance with extruded polystyrene foam (XPS). LDF manufactured with eMDI resins showed the highest physical properties such as thickness/length swelling by water absorption and bending strength.

Synthesis of Polyurethane Foam with Soybean Oil (콩기름을 이용한 폴리우레탄 포옴의 합성)

  • Yang, Do Hyeon;Lee, Kwang Young;Shin, Jae Sup
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.731-736
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    • 1999
  • The polyol was synthesized from soybean oil. Soybean oil was epoxized with peracetic acid, and was reacted with methanol in a sulfuric acid catalyst. OH value of synthesized polyol was 186(mg KOH/g). The polyurethane foam was synthesized with silicon type B-8409 as a surfactant, distilled water as a blowing agent, dimethylcyclohexylamine as a catalyst, and polymeric MDI. The density, the compressive strength, the compressive modulus, and the cell structure of the synthesized foam were investigated. The foam was prepared with changing the mole ratio of MDI, and the amount of water, surfactant, and catalyst. As the MDI index was increased, the density and the compressive property of the foam were increased.

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