• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.5
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• pp.289-296
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• 2016

The availability of NMP, a solvent used in the manufacturing process of cathode material for lithium ion battery, depends on importation, and the price remains high because of the monopoly of BASF and ISP. For these reasons, most Lithium ion battery manufacturers reuse NMP after recovering it from the exhaust air in the drying process. In Korea, absorption method is mainly used for recovering NMP from the absorption tower using the hydrophilicity of NMP. However, this system has a few disadvantages, such as low purity (80％) of the recovered NMP and 100％ emission due to high water content of the treated gas. In this study, we develop a hybrid NMP recovery system by combining cooling condensation method with concentration method, by which it is possible to obtain an NMP recovery rate of 99.6％, and a high purity (96.1％) of the recovered NMP.

• Polymer(Korea)
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• v.24 no.2
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• pp.194-200
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• 2000

The diffusion coefficients in polyimide/N-methyl-2-pyrrolidone (NMP) systems were proposed using tile Vrentas-Duda's hole free volume theory. Several free volume parameters included in the diffusion coefficients were obtained from the fundamental physical properties of polyimide and NMP and group contribution theory, and the pre-exponential diffusion coefficient, D$_{0}$ was also determined from the dynamic swelling behavior of polyimide in NMP solution. The experimental swelling behavior of polyimide films in NMP was well described by the theoretical one using the proposed diffusion coefficient.t.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.59-60
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• 2007

본 논문에서는 선형 비최소위상(NMP, Nonminimum Phase) 시스템에서 특정 조건을 만족하는 복소수 NMP 영점을 가진 시스템에서 언더슈트가 발생함을 보이고자 한다. 먼저 중복 실수 NMP 영점을 갖는 시스템에서의 언더슈트의 크기를 추정한다. 이를 바탕으로 복소수 NMP 영점을 가진 시스템을 중복 실수 NMP 영점을 갖는 시스템과 나머지 시스템의 합으로 보고 언더슈트가 발생하는 복소수 NMP 영점의 범위를 구한다. 최종적으로 복소수 NMP 영점의 복소수 항이 특정 제시되는 값보다 작을 때 언더슈트가 발생함을 보인다.

• Clean Technology
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• v.24 no.1
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• pp.50-54
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• 2018

In this work, N-methyl-2-pyrrolidone (NMP) was added into diethylenetriamine (DETA) aqueous solution for high $CO_2$ loading via phase splitting of absorbents during $CO_2$ absorption. Immiscible two phases were formed in the range of more than 30 wt% of NMP in 2 M DETA + NMP + water absorbents because of low solubility of DETA-carbamate in NMP solution. As the composition of NMP in the absorbents increased, the difference of $CO_2$ loading between each phase increased and the volume of bottom phase decreased. In $CO_2$ absorption in packed column by 2 M DETA + NMP + water absorbents, the absorption rate decreased in the range of more than 40 wt% of NMP. It is due to the increasing of mass transfer resistance in liquid film of absorbents at the high concentration of NMP. DETA + NMP + water absorbent is expected as the promising one for reducing the regeneration energy of absorbents according to volume reduction of $CO_2-rich$ phase.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.34-35
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• 1994

Tube-in-orifice형태의 spinneret을 제작하여, polyethersulfone을 재질로 하는 capillary membrane을 건습식방사공정을 통해 제조하였다. 기공형성계는 PVP를, 용매는 NMP/DCM을, 내부응고제는 물과 NMP의 혼합물을, 외부응고제는 냉각수를 사용하였다. 내부응고제의 NMP농도에 따른 막의 형태와 microstructure를 연구하였다. 내부응고제가 약한 응고력을 가질 때 macrovoid가 없고, 내부의 활성층이 치밀한 막을 얻을 수 있었다. PES-NMP/DCM-PVP조성(25-44/11-20)의 용액으로, 40% NMP수용액을 내부응고제로 사용하여, 막을 제조하고 이를 모듈화하여, 한외여과실험을 한 결과, MWCO 8,000인 모듈이 얻어졌으며, 이 모듈의 Flux는 1기압에서 $1.44 \times 10^{-5}m/sec$이었다.

• Clean Technology
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• v.13 no.4
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• pp.257-265
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• 2007

As a basic study for the development of pilot-scale distillation process of waste photoresist strippers from semiconductor industry, lab-scale experiments for the recovery of NMP (N-methy1-pyrrolidione) and BDG (Butyldiglycol) from waste photoresist strippers have been made using a spinning band vacuum distillation column. Purities of NMP and BDG obtained from the present experiments were higher than 99.5%. Furthermore, water content was less than 1000 ppm, color grade(APHA) less than 50, most metal contents except sodium less than 1 ppb. Those results indicate that NMP and BDG reclamed by distillation satisfy the their specifications required for the formulation of new photoresist strippers. Recovery rate of NMP and BDG was 96 and 53%, respectively, for type A, and 93 and 57%, respectively, for type B waste PR stripper solution.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.4
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• pp.734-744
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• 2002

The purpose of this study was to evaluate the protective effect of Kamicheonggan-tang(KCGT) on pre-hepatocarcinogenesis induced by N-nitrosomorpholine. The studied using blood chemistry, lipidperoxidation, antioxidant, immunohistochemistry and morphological change. The results were obtained as follows. In the pre-hepatocarcinogenesis induced by NMP, serum AST, ALT, ALP and total bilirubin were not changed in NMP and NK treated group after 1 st week, but desreased in NK treated group after 4th week as compared with NMP treated 4th week group. The content of GSH was similary to in NK treated groups as compares with data of normal group. The content of MDA was increased in NK treated group after 1st and 4th week, and more increased in the NMP treated group than those of their NK treated group. The immunohistochemically, stain of GST-p, positive lesions of KCGT were significantly decreased than those of NMP treated group. The histopathologically, fat changes, nucleotic changes, oval cell and inflammatory cells in periportal were observed in NMP treated fater 4th week, but those were significantly decreased from 4th week in the NK treated group. And the enlarged nucleus was not changed in KCGT treated group, but increased in NMP treated group after 1st and 4th week. The ultrastructurally, nucleotic changes, glycogen degeneration, lipid droplet and rER fragmentation were observed in NMP treated group after 4th week, but those changes were significantly decreased from 4th week in the NK treated group. These results suggested that KCGT extracts has protective effect on prehepatocarcinogenesis by NMP, might be usefully applied for clinical treatment of hapatic disease and also it was necessary to do more studies about its mechanisms.

• Applied Chemistry for Engineering
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• v.1 no.1
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• pp.73-82
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• 1990

Rosin-maleic anhydride adduct (RMA) was synthesized from rosin and maleic anhydride. The polyamideimides were obtained by reacting the adduct with two aromatic diisocyanates using sodium methoxide as catalyst. The yield and the inherent viscosity of polymers obtained by the reaction in NMP solvent were low because of the possible reaction of NMP solvent with diisocyanate monomer. The polymers were synthesized in solvent mixture of NMP and cosolvents such as xylene, acetophenone, benzonitrile, and nitrobenzene in order to minimize the side reaction of NMP with diisocyanates. The yield of polymer obtained by the reaction in NMP-nonpolar cosolvent mixtures was about 70% and that obtained by the reaction in NMP-polar cosolvent mixtures was over 90%, respectively. The polymers were either amorphous or poorly cystalline, and soluble only in highly polar solvents. The inherent viscosity of polymers ranges from 0.12-0.26dl/g. The results of thermal analysis showed that the polymer had good thermal stability with initial decomposition temperature over $330^{\circ}C$.

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.25-27
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• 1998

나프탈렌으로부터 제조된 메조페이스 핏치(NMP)와 개질된 등방성 콜타르 핏치(MCP)의 방사성을 유변학적거동에 기초해 설명하고자 시도되었다. 기본적으로, 방사성은 l/4, l/l, 4/1(wt. NMP/wt. MCP)로 블렌드비를 달리 하면서 shear rate를 증가시켰을 때 등방성의 농도가 클 경우 급격한 점도 감소로 cohesive fracture의 원인이 됨을 관찰할 수 있었고 NMP가 증가할수록 탄성에너지 값이 전형적인 고분자의 거동처럼 응답하는 tan $\delta$값의 임계점이 고주파수영역으로 이전되어 최대값을 나타내었고 임계점보다 낮은영역에서 상대적인 크기는 NMP가 증가함에 따라 작아지는 현상을 관찰할 수 있었다.(중략)

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.115-120
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• 2010

The formidable barrier property of the stratum cornemum and the high hydrophilicity of active ingredient make it difficult to permeate through the skin and reach to its site of action. The aim of this study was to investigate the effect of chemical penetration enhancers on the skin permeation of a hydrophilic cosmetic active ingredient, such as arbutin. The enhancing effects of N-methyl-2-pyrrolidone (NMP) on the permeation of a hydrophilic cosmetic active ingredient were evaluated by using Franz diffusion cell. The study indicated that NMP has considerable influence on the skin permeability. NMP was not only the most effective enhancer but also increased the skin permeability of arbutin approximately 1.3~1.5 fold compared with control without penetration enhancer. The lag time did not change with NMP, which suggested no effect of NMP on skin lipid fluidity. This suggest that arbutin co-permeated with NMP. The results indicate NMP is effective enhancer of a hydrophilic cosmetic active ingredient in penetration, with potential applications for drug delivery system.