• 폴리머
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• 제24권6호
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• pp.744-750
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• 2000

PU계 유겔화제를 제조하기 위하여 soft segment로서 친유성을 갖는 polyether계 polyol인 PPG와 PTMG를 사용하고 hard segment로는 TDI를 사용하였다. PPG와 PTMG의 평균 분자량을 각각 1000, 2000, 3000으로 변화시키며 실험한 결과, PPG의 경우 분자량이 증가할수록 유겔화율은 290%에서 130%로 감소하였으며, PTMG의 경우 분자량이 증가할수록 310%에서 250%로 감소하였다. 친수성인 EG를 투입한 경우에 유겔화율은 EG를 첨가하지 않은 경우보다 약 2배 증가하였다. 이는 친수성기의 함량이 증가할수록 물/기름 혼합물에서의 prepolymer의 분산도 증가에 기인한 것으로 판단되며 PPG의 유겔화율은 290%에서 1120%로 증가하였고, PTMG의 유겔화율은 310%에서 1310%로 증가하였다.

• 접착 및 계면
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• 제3권2호
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• pp.1-8
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• 2002

물과의 발포반응에 의해 유츌유를 겔화할 수 있는 폴리우레탄 NCO prepolymer를 제조하기 위하여 폴리올(PTMG 및 GP)과 이소시아네이트(TDI)를 사용하여 NCO prepolymer를 합성하였다. 폴리올 각각의 분자량에 따라 합성한 NCO prepolymer를 이용하여 초기 유출유와 에멀젼된 유출유 그리고 유출유의 종류에 따라 유겔화율을 측정하였다. Bunker B 초기 유출유에 대하여 3관능성 폴리오인 GP1000의 경우 440%의 유겔화율은 나타내었으며, 유출유와 해수가 에멀젼(emulsion)된 상태에서는 2배 정도가 증가한 958%의 유겔화율을 나타내었다. 또한 Bunker B에 비해 점도가 높은 Bunker C의 에멀젼된 상태에서는 1098%의 유겔화율을 나타내었다. 사슬연장제가 투입된 2관능성 폴리올인 PTMG1000의 경우에는 에멀젼된 Bunker B에 대하여 910%의 유겔화율을 나타내었으며, 에멀젼된 Bunker C에 대하여 923%의 유겔화율을 나타내었다. 3관능성 폴리올을 사용하여 제조된 NCO prepolymer의 경우, 형성된 폴리우레탄 겔은 부드럽고 강한 특성을 가져 회수에 용이한 상태를 나타내었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.359-365
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• 1999

We have evaluated the performance and some physical properties of 25 automotive engine oils (21 domestic and 5 imported products) which are purchased on the market to verify the API(American Petroleum Institute) or ILSAC(International Lubricant Standardization and Approval Committee) certification marks attached on the products and to determine the necessity of the quality control of the engine oils on the market. 12 test items are chosen according to API engine oil specification, which are flash point, pour point, cold cranking simulator apparent viscosity, pumping viscosity, gelation index, HTHS(High Temperature High Shear viscosity), foam, high temperature foam, filterability, volatility, high temperature deposit(TEOST), phosphorus content. We have found one product which did not meet the API specification on gelation index, one on HTHS, four on foam, and one on volatility, which implies that the quality control system is in need to check the fidelity of the certification marks attached on the engine oils being marketed. In addition, this works raises the necessity of the upgrade of the present Korean engine oil specification.

• Macromolecular Research
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• 제14권3호
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• pp.365-372
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• 2006

Poly[styrene-b-(ethylene-co-butylene)-b-styrene](SEBS) triblock copolymer was studied by dissolving the ethylene butylene midblock in selective hydrocarbon oils. These oils differ in their aromatic, paraffinic and naphthenic content. Dynamic rheological studies showed that the storage modulus (G') exceeded the loss modulus (G') for all the gels over the entire range of frequency, thereby confirming them as physical gels. However, the behavior of G' and G' as a function of frequency depended primarily on the oil type. The gelation melting temperature decreased drastically with increased oil aromaticity. Small angle X-ray scattering studies revealed that the maximum interdomain interference shifted to a higher angle depending on the composition and type of hydrocarbon oil.

• 폴리머
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• 제29권4호
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• pp.369-374
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• 2005

본 실험에서는 레몬 오일을 함유한 알긴산 칼슘 마이크로캡슐을 에멀션-내부 젤화법으로 제조하였으며, 방출실험을 통하여 아로마테라피의 가능성에 대해 살펴보았다. 적외선분광분석(FT-IR)과 시차주사열량계(DSC)를 통해 레몬 오일의 봉입 여부를 확인하였고, 제조된 마이크로캡슐의 직경 및 형태를 주사전자현미경(SEM)으로 관찰하였다. 제조된 마이크로캡슐은 평균 $4\~7$um직경 및 $50\~85\%$의 캡슐화를 보였으며, $37^{circ}C$에서 적외선 수분계(IMDB)를 통한 방출실험 결과. 알긴산 및 $CaCl_2$의 농도가 증가할수록 가교밀도가 증가하므로 레몬 오일의 방출률이 감소함을 관찰할 수 있었다. 또한, 물리적 압력을 통한 방출실험을 실시함으로써, 캡슐벽의 붕괴와 방출속도가 외부적인 요인에 의해 방출속도를 제어할 수 있음을 확인하였다.

• 한국안전학회지
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• 제18권3호
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• pp.94-100
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• 2003

Gel-like compounds containing flammable solvents were prepared to use fur cleaning agents in field of innovative industries and general purposes. And experiments were conducted to improve the defects of liquified flammable solvents from the view point of safety and health hazards. Flammable solvents used in this study were several single component flammable solvents(turpentine oil, N-methyl-2-pyrrolidone(NMP), d-limonene) and multi component flammable solvent(gasoline and ethanol). For gelation of flammable solvents, commercially Known as Aerosil(equation omitted) 200 fumed silica and triethanolamine(TEA) were used as gelation agent dispersant. The analyses on properties of gel-like compounds was studied by gelation and viscosity test pH test, volatility test and differential scanning calorimetry(DSC) measurement. The experimental results indicate that gel-like compounds containing flammable solvents have pH stability, high viscosity, volatile organic compounds(VOC) control by the decrease of volatility and odor component generation, fluidity control etc. From the experimental values, it can be predicted that the safety in the working place is improved by manufacturing flammable solvents into gel-like compounds.

• 식품기술
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• 제24권3호
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• pp.377-387
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• 2011

• 한국안전학회지
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• 제21권1호
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• pp.86-91
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• 2006

Oil spills caused by the accidents have been occurred from house and factory waste, grounded tanker, the rupture of storage tank and oil pipelines, the deterioration of various industrial facilities, etc. Many oil spills result in contamination of shorelines and workplace. Fire and explosion may happen from these spills. There are several technologies used for clean-up application, which include use of oil dispersing agents, absorbents, solidifiers, booms and skimmers by physical, chemical, and biological methods. Methods for oil spill clean-up operation are classified into the absorption type, gel type and self-swelling type. Porous materials with oil absorptive properties are classified into micropore, mesopore, and macropore depending on their pore sizes. Recently, new porous materials with smaller size have been developed, but the selective oil absorption in water-in-oil interface demonstrates the macro pore size. In this study oil absorption effects were evaluated using the organic porous materials with a complex function of gel type and swelling type. Samples were subjected to analysis by FT-IR spectroscopy and were characterized in terms of gel formation and morphologies. Oil sorption capacity, pressure retention force and gel strength were also measured. From these results, the physicochemical reactivity before and after gelation was verified and the industrial applications of clean-up operation were suggested.

• 청정기술
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• 제23권3호
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• pp.270-278
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• 2017

본 연구는 미세유체 장치에서 매우 균일한 펙틴 하이드로젤 미세섬유를 부분젤화법을 통해 손쉽게 제조하는 방법을 소개한다. 펙틴 수용액과 이와 섞이지 않는 칼슘이 분산된 오일용액 사이의 수력학적 변수들을 조절하여 펙틴 수용액의 흐름을 안정적으로 늘어진 유동을 형성하고 두 상의 계면에서 칼슘 이온의 킬레이트화 반응으로 펙틴 수용액을 부분젤화 시킨다. 부분젤화된 펙틴 수용액은 미세유체 장치 외부의 염화칼슘 수용액에서 오일 용액과 상분리 되고 완전히 젤화되어 미세섬유로 제조된다. 펙틴 하이드로젤 미세섬유의 굵기는 초기 주입되는 펙틴 수용액의 부피유속을 조절함으로써 재현성 있게 제어된다. 제조된 펙틴 하이드로젤 미세섬유의 직경은 200에서 500 마이크로미터 범위이며 모든 두께 조건에서 5% 이하의 변동계수를 가짐으로써 매우 균일함을 증명하였다. 또한 펙틴 하이드로젤 미세섬유에 생체물질을 단일공정으로 고정화 함으로써 생체물질 담지체나 조직공학의 지지체로써 사용될 수 있는 가능성을 보여준다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.370-370
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• 2006

Thermoplastic elastomer gels, which has molecular networks composed of a microphase-separated multiblock copolymer swollen to a large extent by a low volatility mid-block selective solvent such as white oil have various applications. In this particular study, the effect of several network-forming nanoscale fillers such as two different graphite particles and carbon nanotube on the properties of TPE gels prepared from a microphaseordered poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymer with an EB compatible white oil was studied. The linear viscoelastic behavior, sol-gel transition, x-ray diffraction and mechanical properties were discussed. The properties of thermoplastic elastomer gels hybrid with graphite prepared by mixing Poly(styrene-b-ethylene-co-butylene)-b-styrene) with paraffin oil and different amount of expandable graphite were found to increase the mechanical properties at only lower graphite concentration but tends to decrease when paraffin oil/SEBS ratio is lower. The gelation temperature is the same for all TPE gels with different amounts of graphite. Both storage (G') modulus loss (G") modulus of TPE gels slightly increase with addition of graphite.