• Elastomers and Composites
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• 제55권3호
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• pp.205-214
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• 2020

A series of wholly aromatic polyhyroxyamide (PHA) copolymers were prepared by direct polycondensation reaction of isophthalic acid and diacids containing bulky units with 3,3'-dihydroxybenzidine. The inherent viscosities of the PHAs measured at 35℃ in DMAc solution were in the range of 0.31-0.56 dL/g. The solubility study revealed that the PHAs were readily soluble in aprotic solvents such as, dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), and N-methyl-2-pyrrolidone (NMP) at room temperature and in less polar solvent such as pyridine. However, the polybenzoxazole (PBO) copoymers were quite insoluble in all organic solvents except partially soluble in concentrated sulfuric acid and partially soluble in NMP containing LiCl. The PBO copolymers showed maximum weight loss temperature in the range of 593-632℃ and high char yields in the range of 65.0-71.2% at 900℃ in a nitrogen atmosphere.

• 반도체디스플레이기술학회지
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• 제14권4호
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• pp.8-12
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• 2015

As NMP (N-Methyl-2pyrrolidone) is becoming important in many fields, the demand for it is also rising rapidly. With its chemical property of high boiling point, low vapor pressure and high water solubility, it is easy to recover it after processing. Therefore, it is increasingly needed to develop a system that effectively recovers NMP solvent. The study produced a system modeling using AMESim software before developing high purity solvent recovery (HPSR) system to recover NMP solvent. Then, it verified reliability by comparing the simulation model with the test result.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.166-169
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• 2004

Microfiltration membranes were prepared from aromatic polyethersulfone (PES) polymer, using aprotic solvent (N-methyl-2-pyrrolidone, NMP) and non-solvent additive (2-methoxy ethanol, 2-ME) by the phase inversion co-process of the vapor-induced phase inversion (VIPI) and the nonsolvent-induced phase inversion (NIPI). According to the change of the additive amount, the solvent amount and the relative humidity, membrane characterization was studied. The non-solvent additive in casting solution played an important role in membrane morphology. During the vapor-induced phase inversion, the relative humidity led to water sorption on the surface of casting dope at which pore formation was generated. The prepared membranes were characterized by scanning electron microscope observations, measurements of capillary flow porometer and pure water flux (PWP). Also the thermodynamic and kinetic properties of membrane-forming system were studied through coagulation value, light transmittance and viscosity.

• 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.

• 한국산업융합학회 논문집
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• 제12권4호
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• pp.193-202
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• 2009

In the preparation of anion charged asymmetric ultrafiltration membranes by the conventional phase inversion method, several variables could be adjusted to control membrane permeations. The anion charged materials and its original polymer have good solubility in N-methyl-2-pyrrolidone. The membranes having a hydrophilic property were less fouled the membrane prepared from the original polymer. The preparation conditions, operation conditions, and hydrophilicity of polymer have played an important role in determining the permeation properties of membranes.

• Macromolecular Research
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• 제17권11호
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• pp.901-906
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• 2009

Several aromatic optically active polyamides (PA)s were synthesized from 5-(2-phthalimidiylpropanoylamino)isophthalic acid with various aromatic diamines via direct polycondensation with triphenyl phosphite and pyridine in the presence of calcium chloride and N-methyl-2-pyrrolidone under microwave irradiation and conventional heating conditions. Under the optimized conditions, the reaction mixture was irradiated for 2 min. with a 100% irradiation power (900 W). The resulting polymers were obtained in high yield and moderate inherent viscosity ranging from 0.35 to 0.60 dL/g. All synthesized polymers showed excellent solubility in amide-type solvents. Thermogravimetric analysis revealed a 10% weight loss temperature and char yield at $600^{\circ}C$ in a nitrogen atmosphere of > $350^{\circ}C$ and > 58%, respectively, which suggests that the resulting PAs have good thermal stability.

• 한국전기전자재료학회논문지
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• 제32권3호
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• pp.252-255
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• 2019

Black phosphorus (BP) is a potential candidate for an anode in lithium ion batteries due to its high theoretical capacity and the large interlayer spacing in the monolayered phosphorene form, allowing for lithium intercalation/deintercalation. In this study, large-scale exfoliation of bulk BP was accomplished using a solution of NaOH and N-methyl-2-pyrrolidone (NMP), yielding phosphorene, which can be assembled into nanoflakes using electrophoretic deposition (EPD). Through the systematic addition of NaOH and subsequent sonication, BP nanoflakes were obtained in high yields by EPD, allowing for the integration of these nanoflakes into an anode in the film state. Anodes with a charge/discharge capacity of 172 mAh/g at a rate of 200 mA/g were obtained, which are promising for battery applications through various post-film treatments.

• Macromolecular Research
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• 제12권3호
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• pp.263-268
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• 2004

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4'-oxydianiline, and N,N -dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D$\_$sf/). The maximum value of D$\_$sf/ we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D$\_$sf/ of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D$\_$sf/ to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD 100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

• Korean Chemical Engineering Research
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• 제46권5호
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• pp.965-970
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• 2008

접촉분해경유의 산화반응후 포함된 산화황화합물을 분리하기위해 다양한 용매를 사용하여 용매추출에 관한 연구를 수행하였다. 용매로는 극성을 가진 물, N-메틸피놀리논, 에틸아세테이트, 디메틸포름아마이드, 이소프로필알코올, 아세토니트릴, 메탄올등을 사용하였다. 실험결과, 접촉분해경유와 용매와의 층분리는 적절한 양의 물을 첨가한 경우에 이루어졌으며, 물과 N-메틸피놀리논을 혼합한 혼합용매가 접촉분해경유로부터 산화황화합물의 선택적인 분리에 가장 적절하였다. 또한 접촉분해경유로부터 황화합물을 99.5% 이상으로 제거하기 위해선, 4단 정도의 평형추출이 필요하였다.

• 한국식품과학회지
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• 제32권5호
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• pp.1015-1021
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• 2000

현재 재배되고 있는 흑미 중 수원 415호와 진도를 n-pentane과 diethylether 혼합용액(1:1, v/v)을 추출용매로 사용하여 SDE방법으로, 취반된 흑미로부터 휘발성 향기 성분을 추출하였다. 이 향기 추출물을 정제 농축하여 GC와 GC/MS로 분석한 후 GC 분석에 의한 RI 및 GC/MS 분석에 의한 mass spectrum을 표준물질의 분석 자료와 비교, 확인함으로써 휘발성 향기 성분을 동정하였고, 내부 표준물질을 이용하여 이들 성분을 정량하였다. 수원415호와 진도에서 각각 91, 82종의 화합물이 분리되었다. 수원415호에서는 alcohol류 26종, ketone류 15종, ester류 11종, aldehyde류 10종, hydrocarbon류 9종, acid류 5종, 황화합물 9종, 질소화합물 3종, furan 화합물 3종이었고 동정된 물질 중에서 hexadecanoic acid, acetic acid, 1,2-ethanediol, guaiacol, ethyl acetate, 2,3-dihydrobenzofuran, ethanol, ethyl hexadecanoate, methyl 9,12- octadecadienoate, hexanol, ethyl formate, hexanal, 2-pentanone이 수원 415호 흑미의 주요한 성분으로 확인되었다. 진도 흑미에서 분리 동정된 성분으로는 alcohol류 28종, ketone류 14종, ester류 12종, aldehyde류 9종, hydrocarbon류 5종, acid류 4종, 황화합물 4종, 질소화합물 3종, furan 화합물 3종이었고, hexadecanoic acid, guaiacol, acetic acid, 2,3-dihydrobenzofuran, hydroperoxy pentane, ethyl acetate, methyl 9,12-octadecadienoate, 2-nonanone, ethyl hexadecanoiate, ethyl formate, ethyl 9-octadecenoate, hexanol, 2-pentanone, 3-methyl-1-butanol이 동정되어 이러한 성분들이 진도 흑미의 주요한 성분으로 확인되었다. 미량이지만 향기의 발현에 영향을 미칠 것으로 생각하는 1-acetyl-2-pyrrolidone과 ${\alpha}-pyrrolidone$이 동정되었다.