• Applied Chemistry for Engineering
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• 제9권4호
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• pp.491-496
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• 1998

The composition of isocyanates and polyols influence prepolymeric properties of adhesive and calking sealant based on polyurethanes (PU). One component moisture curing prepolymers, which reacted with surface humidity of substrate, were synthesized in several kinds of composition. Reactivity, structural change and properties of the prepolymers were studied as a preliminary step to manufacture PU based adhesive and sealant. To study the effects of mole ratio ([NCO]/[OH]), we used toluene diisocyanate (TDI), 4, 4'-diphenylmethane diisocyanate (MDI), and ether-polyols such as PTMG and PPG which have good resistance to hydrolysis and excellent low-temperature properties. The each prepolymers could be prepared in different molecular weight without any significant structural change. The mole ratio 1.78 of [NCO] to [OH] showed the fastest reactivity. It was confirmed that effect of polyols was larger than that of isocyanates on the prepolymer in reactivity. Several kinds of compounds were manufactured with each prepolymer, and tensile and properties were tested. And the optimum quantity of curing accelerator for the PU was 0.05~0.1%. In the tensile test, TDI based PU was superior to MDI based PU, and also PTMG based PU was superior PPG based PU.

• 월간산업보건
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• 통권328호
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• pp.55-59
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• 2015

톨루엔-2,4-디이소시아네이트, 톨루엔-2,6-디이소시아네이트 각각 또는 두 이성체 혼합물(TDI)에 대하여 TLV-TWA는 0.005 ppm, TLV-STEL은 0.02 ppm으로 직업적 노출기준을 권고하고 있다. 본 수치는 호흡기에 대한 영향과 과민성 반응에 대한 높은 발생 가능성을 최소화하기 위한 것이다. 산업현장에서 증기상 TDI 물질은 점막, 호흡기계에 심한 자극을 일으켜 천식과 같은 증후군 등 급성 발작을 유발한다. 고농도에 노출시 심한 기관지 경련, 폐렴, 폐부종, 두통, 불면증과 기관지염으로 이어질 수 있다. TDI에 상당 부분 노출되면 대부분의 사람들은 위와 같은 건강 영향을 경험하게 된다. 심지어 처음 노출되었을 경우에도 발생된다. TDI 노출 관련 연구자들은 일반 근로자들이 0.02 ppm 수준 정도로 가끔 노출되는 경우 건강 영향을 받지 않으나, 0.02 ppm이 무영향 수준으로 간주될 수 있는 그 어떠한 증거도 없다고 결론을 내렸다. TDI에 일단 감작되면 몇몇 근로자들은 노출 중단 후에도 몇 년 동안 건강 영향 증세가 지속된다. 따라서 감작제 표기는 호흡 노출을 통한 알레르기성 감작 증세의 명확한 증거로서 권고된다. A4(비발암성 물질) 표기는 생쥐와 흰쥐들을 대상으로 수행된 위장관 투여 연구와 흡입 연구들을 통해 얻어진 동물 노출 데이터에 근거하여 설정되었다. 불충분한 데이터로 피부 표기는 권고되지 않았다.

• Journal of Environmental Science International
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• 제23권11호
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• pp.1909-1918
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• 2014

In this experiment no solvent based polyurethane(PU) adhesives were prepared with the polyol, isocyanate, dioctyl phthalate(DOP), 2-hydroxyethylacrylate(2-HEA) and other acrylate monomers. The softenening point of the PU adhesives measured by Ring & Ball method were examined in the present study. And adhesion strength and mechanical properties such as tensile strength and 100% modulus of the PU adhesives were evaluated by Universal Test Machine. The experimental results showed that increase of both DPE-41, benzoylperoxide(BPO) and toluene diisocyanate(TDI) increased softenening point, adhesion strength, tensile strength and 100% modulus. However as DOP content increased sofenening point, adhesion strength decreased and tensile strength, 100% modulus also decreased.

• Journal of Korean Society of Water and Wastewater
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• 제14권1호
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• pp.76-83
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• 2000

This research is about wastewater containing non-biodegradable TDI(Toluene Diisocyanate) that is treated by the activated carbon adsorption method. In the case of the Fenton oxidation process being applied to the existing process, optimal pH, reaction time, chemical dosing amount, removal rate, and cost were investigated. A pilot plant test was applied after finding optimal conditions with lab experiments. The optimal conditions were pH 3~5(COD removal rate 84~88%) and reaction time 30min~1hr. In higher $H_2O_2$ dosing amount, COD removal rate was a little higher. But there was little difference in the removal rate according to $FeSO_4{\cdot}7H_2O$ dosing amount. Treatment cost was economical in the case of the Fenton oxidation process being operated earlier than activated carbon adsorption system. But chemical dosing point, chemical mixing effect, chemical dosing amount, removal rate, and the cost of facility and others must be considered in practical process.

• Environmental Analysis Health and Toxicology
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• 제19권3호
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• pp.307-314
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• 2004

합성화학물질들이 환경으로의 유입은 인체에는 물론 환경생태계에 많은 영향을 미치므로 이들의 유해성 검증은 매우 중요한 일이라 할 수 있다. 실제 산업체에서 사용되는 수많은 화학물질들의 유전적 손상 유발유무는 유해성검증에서 무엇보다 중요한 일이라 할 수 있다. 이에 산업체 공정과정에서 널리 사용되는 것으로 알려진 11종의 합성화학물질에 대해 마우스의 골수 세포를 이용한 in vivo소핵시험을 수행하여, 소핵형성 유발유무를 관찰하였다. 양성대조군으로 사용된 mitomycin C는 음성대조군과 비교시 유의하게 소핵을 유발하는 반면, 비교적 마우스에서 높은 50%치사량을 보이는 thiourea, 2,4-dichlorophenol 및 2,4-toluene diisocyanate 등의 합성물질들을 비롯한 나머지 8종의 물질들은 본 실험결과 통계적으로 유의하게 소핵을 유발하지 않는 것을 관찰 할 수 있었다.

• Textile Coloration and Finishing
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• 제20권4호
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• pp.31-42
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• 2008

Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and ethylenediamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of prepared polyurea microcapsules was smaller and the surface morphology of the microcapsule prepared by the PVA as protective colloid was much smoother than the gelatin. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. PET containg microTCPs have a higher activation energy of decomposition, higher char content and lower heat of combustion.

• Textile Coloration and Finishing
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• 제9권5호
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• pp.63-74
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• 1997

Polyurethane microcapsules were synthesized by interfacial polymerization in an aqueous poly(ethylene glycol) dispersion with ethylenediamine as chain extender of toluene diisocyanate in perfume oil using poly(vinyl alcohol) as the stabilizing agent. The effect of chemical structure on the average particle size and distributions, morphologies, and thermal properties to design microcapsules for the sustained release system was investigated. It came to be known that polyurethane microcapsules with ethylene diamine as chain extender had a rounder, more permeable and controlled release membranes. And the release test of polyurethane microcapsules with different soft segment content was done to certify the effect of long methylene chain. According to the higher molecular weight of polyether polyol, the release rate of microencapsulated disperse dye molecular was faster.

• Textile Coloration and Finishing
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• 제9권5호
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• pp.52-62
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• 1997

Abstract Polyurethanes have been designed and fabricated into membranes with unique separation properties. Moreover, polyurethane microcapsules also have been reported actively as controlled release materials for their excellent blood compatibility, tensile strength and permeability. In this study, polyurethane microcapsules were synthesized by interfacial polymerization in an aqueous poly(ethylene glycol) dispersion of toluene diisocyanate in perfume oil using poly(vinyl alcohol) as the stabilizing agent. The effect of a few important process conditions on the average particle size and distributions, morphologies, and thermal properties to design microcapsules for the sustained release system was investigated.

• Textile Coloration and Finishing
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• 제19권5호
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• pp.30-36
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• 2007

Cypermethrin-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of the polyurea microcapsules was smaller and the surface morphology of the PVA was much smoother than gelatin. In addition the release behavior was much more controlled and better sustained. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. The release behavior of the core material changed according to the concentration. As the gelatin concentration was increased, a more controlled and sustained release behavior was observed. However, in the case of PVA, the increase of PVA concentration lead to a more rapid release rate.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.1392-1394
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• 2010

단일염기다형성 유전형 자료에 대한 유전자형을 얻어내는 기술(genotyping)이 발달함에 따라 분석해야 하는 SNP의 개수가 수십만 개로 증가하였다. 따라서 기존의 연관성 분석(association study)연구 방법을 그대로 적용시키기는 어렵다. 본 논문에서는 상호정보량(mutual information)과 Multifactor dimensionality reduction을 이용하여 대용량의 SNP 유전형자료를 분석하는 방법을 제안하였고, 이 방법을 toluene diisocyanate-induced asthma에 대해 실험해본 결과 높은 판별력을 보이는 모델을 찾을 수 있었다.