• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.49-50
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• 1995

고분자분리막을 이용한 기체 혼합물의 분리방법은 심냉법(cryogenic process), 가압기체흡착법(Pressure adsorption)과 더불어 상업적으로 중요한 기체분리공정으로 부각되고 있다. 특히 고분자막 중 Polyimide 막은 열적, 화학적으로 안정하고 기체에 대한 선택성이 높으며 기계적 성질이 뛰어나 좋은 막소재로 알려져 있다. 그러나 투과도와 선택도사이에 일반적으로 Trade-off 현상이 있어서 투과도와 선택도를 동시에 향상 하려는 연구가 수행중에 있다. 본 연구에서는 높은 산소투과도를 갖는다고 보고된 6FDA-p-TeMPD막에 hexafluoropropene (HEP)으로 Plasma polymerization을 시키거나 CF$_4$, Ar기체가 플라즈마처리하여 투과특성을 개선시키고 이를 비교 고찰하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.28-29
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• 1994

일반적으로 polyimide는 열적, 화학적으로 안정하며 좋은 기계적 성질을 갖고 있고 기체투과 특성이 뛰어나므로 훌륭한 막 소재로 알려져 있다. 그러나, 높은 선택도를 나타내면 투과도가 떨어지고 투과도가 높으면 선택도가 떨어지는 일반적인 고분자 막이 보이는 경향을 따르므로, 본 연구에서는 이례적으로 높은 산소 투과도를 보이는 6FDA-pTeMPD polyimide와 높은 선택도를 나타내는 6FDA-mPDA polyimide을 공중합 시킴으로써 각각의 homopolyimide로서는 얻을수 없는 개선된 기체 투과도와 선택도를 얻을 수 있으리라 예상하여 연구를 하였다. 조성과 자유용적, 조성과 Tg관계, 조성과 투과도 및 선택도를 조사하여 공중합 하였을때 고분자의 화학 구조와 미시적 구조간의 관계를 규명하여 분자 설계로 적절한 막 특성을 갖는 공중합 막을 합성할 수 있는 정보를 확립하였다.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.359-362
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• 2007

본 실험에서는 Polyimide (PI)의 전구체인 Poly(amic acid) (PAA)의 제조를 위하여 2,2-BIs(3,4-anhydrodicarboxyphenyl)hexafluoropane(6FDA)와 4-aminophenyl sulfone로 PAA를 합성하였다. 이를 열을 가하여 Polyimide가되는 반응을 적외선 분광법을 이용하여 추적하였다. 이미드화 반응은 $80^{\circ}C$에서 1시간, $120^{\circ}C$에서 1시간, $240^{\circ}C$에서 1시간, $250^{\circ}C$에서 1시간, 2경화시킴으로 완결됨을 확인하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.106-106
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• 1997

Cinmetacin, one of the candidate of NSAID of arylacetate group was developed into a prodrug SJ-151 with butendiol group to minimize its gastrointestinal side effects. We studied its excretion and distribution after single oral administration in rats. Male rats were orally administered with 30, 60, 80 or 120mg/kg of SJ-151 and their urine and stool were collected at 0, 6, 12, 24 and 48 hour after administration. To evaluate its tissue distribution, 120mg/kg of SJ-151 was orally given and samples of blood, liver, kidney and brain were taken at 0.5, 1, 2, 4, 8, 24, and 48 hour of administration. As results, less than 0.1% of administered SJ-151 was detected in 48 hour collected urine as its metabolite cinmetacin. 33-50% of administered SJ-151 was observed in 48 hour collected stool as SJ-151. 3-7% of excreted SJ-151 was observed in 48 hour collected stool as cinmetacin. SJ-151 and cinmetacin were not detected in the brain regardless of dosage. SJ-151 was detected neither in kidney nor in liver. Only cinmetacin was observed in both organs with kidney concentrations higher than liver throughout the observation period. On the whole, organ concentration of cinmetacin fluctuated through 0.1-1.5 times that of plasma. As no reports on the metabolism of SJ-151 or cinmetacin in specific organs has been published yet, any detailed explanation of these results needs further study and the plasma concentration profile of rats showed remarkable interspecies difference with dogs.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.62-63
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• 1997

Polyimide는 내열성과 기계적, 화학적 특성이 다른 고분자막에 비해 뛰어나며 선택도 또한 비교적 높기 때문에($\alpha$=3~7) 최근 많은 연구의 대상이 되고 있다. 그러나 소위 trade-off현상으로 알려진 바와 같이 선택도가 높은 고분자 재료는 투과계수가 낮은 단점을 가지고 있어서 (P${_O_2}$=0.1~122) 실용적인 막으로 사용되기 위해서는 이를 개선하는 연구가 필요하다. 본 연구에서는 polyimide 중 투과계수가 가장 큰 것으로 보고된 6FDA-p-TeMPD 막을 제조하여 여러 방법으로 UV처리를 하고 UV처리의 변수에 따른 막의 투과특성을 조사하여 가장 뛰어난 투과특성을 나타내는 최적조건을 찾고자 하였다.

• Korean Journal of Animal Reproduction
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• v.16 no.4
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• pp.317-323
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• 1993

This study was carried out to study effects of the addition level of acetamide and non-permeable cryoprotectants(Ficoll, sucrose) in VS(20% glycerol＋10% ethyleneglycol) and equilibration time on the survival of vitrified mouse morulae. The results are summarized as follows: 1. When 10, 15 and 20% of acetamide were added to the new vitrification solution(20G 10E), FDA-scores of embryos were 4.4(control), 4.4(10%), 3.6(15, 20%), respectively. The addition of acetamide did not affect the survival of forzen-thawed morulae(P<0.05). 2. The survival rate betwen 5 min(3.5) and 10 min(4.6), 10 min(4.6) and 20 min(3.2) of equilibration in 10% sucrose, and 20 min(3.2) and 5 min(4.0), or 10 min(4.3) in 20% sucrose were significantly different(P<0.05). The highest survival(4.6) rate was obtained in mouse morulae equilibrated in VS(20G 10E) containing 10% sucrose for 10 minutes. 3. FDA-score of morulae frozen in the new vitrification solution containing 0, 10, 20 and 30% Ficoll was 4.5, 4.2, 4.4 and 4.6, respectively and had no significant effect among concentrations of Ficoll(P>0.05). The development rate after culture(24h) was 89%(20% Ficoll) and 93%(30% Ficoll), respectively.

• Membrane Journal
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• v.19 no.3
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• pp.237-243
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• 2009

Polyimides synthesized by using 2,2'-bis(3,4-carboxylphenyl) hexafluoropropane dianhydride (6FDA) and 4,4'-diaminodiphenylmethane (DAM) were sulfonated according to reaction times, 5 min to 20 min. And the resulting polyimide membranes were investigated in terms of permeability and separation factor for $N_2$, $O_2$, and $CO_2$ gases. The introduction of bulky group, $-{SO_3}H$, leads to the decreases of both diffusivities and solubilities for all the range of reaction times. At 20 min of sulfonation, the diffusivity and solubility of $N_2$ decrease up to 21% and 26%, respectively. Overall separation efficiencies for $O_2/N_2$ and $CO_2/N_2$ increase as the reaction time increases to 20 min.

• 프린팅코리아
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• v.8 no.6
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• pp.68-70
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• 2009

• Polymer(Korea)
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• v.36 no.4
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• pp.448-454
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• 2012

A poly(amic acid) (PAA) was prepared by reaction of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluropropane (BAPP) in N,N-dimethylacetamide (DMAc). The cast films of the synthesized PAA were thermally treated at different temperatures to create polyimide (PI) films. The heat treatment temperature varied between 80 and $230^{\circ}C$ to investigate the imidization index in relation with the solvent evaporation rates. The progress of PAA imidization was examined using a thermogravimetric analyzer (TGA) and a Fourier transform infrared spectroscope (FTIR) at various time and temperature. The experimental results showed that the imidization index was fast at the initial stage in the presence of solvent, DMAc, reaching the final imidization. When the imidization temperature is high over $200^{\circ}C$, the imidization index decreased because the solvent was evaporated too fast.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.363-369
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• 2006

A simple and an improved methods for the economic analysis of the flood control project has been in previous studies in Korea. In 2004, the Multi-Dimensional Flood Damage Analysis (MD-FDA) was developed and now it is widely used for the economic analysis of flood control project. However, the MD-FDA was developed for general damage assessment and analysis without consideration of specific regional characteristics such as urban and rural areas. To compensate the MD-FDA for the application in urban area, a part of damage estimation components is modified and a component for the flood damage estimation is suggested. The component we suggest is for the consideration of the capability of stormwater pump stations in the study area. When flood is occurred in the urban area, the damage potential is larger than the rural area because of the concentration of human lives and properties. So, many stormwater pump stations are located in the urban area and the inundation depth is estimated by considering the capabilities of pump stations. We also compensate the damage components such as the damages of industrial area, and public facilities for the flood damage estimation of the urban area. The results by the compensated MD-FDA for the urban area application with those by original MD-FDA are compared. As a result the B/C ratio showed 6.75 and 5.51 respectively for the modified and original MD-FDA. This difference might be largely affected by the damage rate of the public facilities.