• 한국응용과학기술학회지
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• 제27권4호
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• pp.461-469
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• 2010

Polyurethane adhesive is used in various fields as flexible packaging materials including a food packaging field. Therefore, the purpose of this study is synthesis of polyurethane adhesive which uses aliphatic isocyanate, and compares with aromatic isocyanate. The isocyanates for this test are toluene-2,4-diisocyanate(TDI), hexamethylene diisocyanate(HDI), 4,4-dicyclohexyl ethane diisocyanate($H_{12}MDI$), and isophorone diisocyanate(IPDI). And, the effect of any other diisocyanate are evaluated by several methods as for curing rate test, accelerate weathering test, and peel strength test. The polyurethane adhesive using curing catalyst and HDI has adhesion strength of about 560 g/15 mm between aluminium foil and nylon, about 1,520 g/15 mm between nylon and CPP. Those parameters are similar to polyurethane adhesive with TDI. Also, in case of curing rate, those are similar to TDI type polyurethane adhesive. Moreover, data of ${\Delta}E$ as color variation by QUV tester is equal to 4.12, as 48% against those of TDI type.

• Environmental Analysis Health and Toxicology
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• 제15권1_2호
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• pp.53-59
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• 2000

The purpose of this study is the development of the simple and precise determination method of ethyl isocyanate (EIC) and propyl isocyanate (PIC) through derivatization using secondary aliphatic amines by gas chromatography with flame ionization detector. The urea derivatives are quantitatively and simultaneously derived from EIC and PIC with secondary aliphatic amines such as dipropylamine, dibutylamine. and dipentylamine in methylene chloride, and confirmed by thin layer chromatography and gas chromatography with mass selective detector. For GC/FID, according to the increasing carbon atom of the amines, the retention time and peak area of the urea derivatives are increased. The instrumental detection limits for EIC and PIC were about 23.3∼34.8 $\mu\textrm{g}$ and 21.6∼28.9 $\mu\textrm{g}$, respectively.

• 한국산업보건학회지
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• 제11권3호
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• pp.249-253
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• 2001

The purpose of this study is the development of the simple and precise sampling and analysis method of methyl isocyanate(MIC) in the work place as their secondary aliphatic amine derivatives by gas chromatography with flame ionization detector. The urea derivatives are quantitatively and simultaneously derived from MIC with secondary aliphatic amines such as dipropylamine(DPA), dibutylamine(DBA), and dipentylamine (DAA) in methylene chloride. The method is based on sampling glass tube in XAD-2 resin which is coated with secondary aliphatic amines. The samples are desorbed by $2m{\ell}$ methylene chloride and analysed using gas chromatography with flame ionization detector(GC/FID). In the results, the detection limit of the overall procedure and reliable quantity are $0.020-0.027{\mu}g$($1.347-1.740{\mu}g/m^3$(0.529-0.684 ppb) based on a 15 L air volume) MIC per sample. The average desorption efficiencies are 97.96 - 101.23 %. The results of versus storage time are high and stable recovery rates.

• 공업화학
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• 제5권4호
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• pp.743-747
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• 1994

Acrylic urethane 수지의 경화반응에서 아크릴수지 중의 carboxylic acid 함유량과 dibutyltin dilaurate(DBTL)의 촉매 효과가 반응속도에 미치는 영향을 검토하였다. 얇은막의 상태에서 acrylic polyol과 지방족 isocyanate의 biuret화합물과의 경화반응은 2차식에 따른다. 그리고 acrylic polyol 중의 carboxylic acid의 양이 반응속도에 미치는 영향은 매우 크며, isocyanate지에 대한 강한 촉매 효과가 나타났다. 한편 carboxylic acid를 함유하지 않은 acrylic polyol에 DBTL을 첨가하면 촉매효과가 많이 나타나지만, carboxylic acid를 함유한 acrylic polyol의 경우에는 그 효과가 적게 나타났다.

• 폴리머
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• 제29권1호
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• pp.59-63
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• 2005

FTIR을 이용하여 폴리(카프로락톤 다이올)과 지방족 이소시아네이트간의 반응속도에 관한 연구를 수행하였다. NCO 피크(2265 $cm^{-1}$)의 흡광도 변화를 통하여 반응속도를 해석하였다. 그 결과, 폴리(카프로락톤 다이올)과 이소시아네이트간의 반응은 전체적으로 단순 2차 반응속도법과 일치함이 확인되었고, 반응온도의 증가에 따라 속도 상수는 증가하였다. 반응속도 상수로부터 구한 활성화에너지는 hexamethylene diisocyanate의 경우 25.4~30.9 kJ/mol, cyclohexylmethane diisocyanate의 경우 16.8~22.1 kJ/mol로 각각 나타났다.

• 공업화학
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• 제20권3호
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• pp.258-265
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• 2009

Poly(tetramethylene glycol) (PTMG, Mw = 2000), dicyclohexylmethane-4,4'-diisocyanate $(H_{12}-MDI)$와 4,4'-diphenylmethane diisocyanate (MDI)의 이소시아네이트 혼합물, 그리고 음이온기로서 dimethylol propionic acid (DMPA)를 사용하여 프리폴리머 혼합법으로 음이온성 폴리우레탄 분산체(PUD)를 합성하였다. 프리폴리머의 중화제로서는 triethylamine (TEA)을, 그리고 프리폴리머의 가지연장제로는 ethylene diamine (EDA)를 사용하였다. DMPA의 몰비율과 혼합이소시아네이트에서 방향족 이소시아네이트의 함양이 PUD의 입자크기와 점도변화에 미치는 영향을 연구하였다. 그리고 또한 DMPA의 몰비율과 방향족 이소시아네이트 함양 변화에 따른 PUD 도막의 기계적 성질과 열적 성질에 대해서도 논의하였다. DMPA의 몰비율이 증가할수록 음이온성 PUD의 입자크기와 점도가 감소하였으나, 동일한 DMPA 함량에서는 이소시아네이트 혼합물 중 방향족 이소시아네이트의 함량이 증가 할수록 입자의 크기와 점도가 증가하는 경향을 나타냈다. 혼합 이소시아네이트의 몰비율이 일정할 때 PUD 도막의 인장강도는 DMPA의 함량이 증가함에 따라 증가하였으나, 신장율은 감소하였다. PUD 도막의 열분해 온도에 있어서, DMPA 함량에 대한 영향은 크게 나타났으나, 방향족 이소시아네이트 함양의 영향은 DMPA 함량이 낮은 조건에서는 상대적으로 크지 않았다.

• Macromolecular Research
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• 제13권5호
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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.

• 한국환경과학회지
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• 제21권4호
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• pp.507-515
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• 2012

To improve the mechanical properties of hydroxyapatite (HA)/waterborne polyurethane (WBPU) composites, the hydroxyl group of HA was modified by urethane reactions: the hydroxyl groups of HA were reacted with aliphatic or cyclic diisocyanate, and then the modified HAs were extended by adding polyol and/or ${\varepsilon}$-caprolactone. Composites were prepared by the prepolymer process method: the modified HA was directly pured into the urethane reaction of isocyanate and polyol. The properties of modified HA/WBPU composites were investigated by thermogravimetric analysis, tensile strength, and water resistance. The results showed that the reactivity of aliphatic diisocyanate to the hydroxy group of HA was faster than that of cyclic one. Comparing to those of pure HA/WBPU composite films, the thermal stability, water resistance, and mechanical properties of the modified composite films increased with a degree of modification of HA.

• Elastomers and Composites
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• 제58권3호
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• pp.121-127
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• 2023

The effect of diisocyanate type on the decomposition temperature of polyurethane (PU) hydrolysis was investigated in a subcritical water medium up to 250℃. PU samples were prepared using different types of diisocyanate: two aromatic diisocyanates (4,4'-methylene diphenyl diisocyanate (MDI) and methyl phenylene diisocyanate (TDI)), one unbranched aliphatic diisocyanate (hexamethylene diisocyanate (HDI)), and two cyclic aliphatic diisocyanates (4,4'-methylene dicyclohexyl diisocyanate (H₁₂MDI) and isophorone diisocyanate (IPDI)). The pressure had no effect on hydrolysis in the range of 70-250 bar. The decomposition temperature of the PU samples increased in the following order: TDI-PU (199℃) < H₁₂MDI ≈ IPDI ≈ HDI (218-220℃) < MDI-PU (237℃). This order of increase in temperature is related to the electron-donating ability of the group to connected to the nitrogen of the urethane unit. When the temperature of the (PU + water) mixture reached the specific decomposition temperature, the PU samples hydrolyzed completely within 5 min into primary amine and 1,4-butanediol. The hydrolysis products from MDI-PU and H₁₂MDI-PU were separated into a liquid phase rich in (BD + water) and a solid low phase rich in amine, whereas the products from TDI-, IPDI-, and HDI-PU existed in a single aqueous phase.

• 한국응용과학기술학회지
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• 제19권1호
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• pp.25-32
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• 2002

Two PU flame-retardant coatings, 2,3-DBPO/N-l00 (DBPON) and 2,3-DBPO/IL (DBPOI), were prepared by curing 2,3-dibromo modified polyester (2,3-DBPO) with isocyanate curing agent Desmodur N-l00 (or Desmodur IL) at room temperature. The physical properties and flame-retardancy of the two coatings were tested and compared. As a result, the pot-life, yellowness index, lightness index difference, $60^{\circ}$ specular gloss, cross-hatch adhesion, viscosity, and accelerated weathering resistance of DBPON were better than those of DBPOI; the fineness of grind of the two coatings were the same; and the drying time, hardness, and abrasion resistance of DBPOI were better than those of DBPON. The flame retardancy of the flame-retardant coatings increased with the content of the flame retarding component, 2,3-dibromopropanoic acid (2,3-DBP); and the LOI values of the two coatings were in a range of $27{\sim}29%$ when the content of 2,3-DBP was 30wt%.