• Bulletin of the Korean Chemical Society
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• v.9 no.3
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• pp.129-132
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• 1988

The stereochemistry of N-acyliminium cyclizations to form decahydropyrrolo[2,1-a]isoquinolin-3(2H)-ones was studied. Particular attention was paid to the stereocontrol by an acetoxy group present on pyrrolidone ring. Two of the three new chiral centers were formed stereospecifically, and the third was controlled by elimination-hydrogenation sequence.

• Bulletin of the Korean Chemical Society
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• v.1 no.4
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• pp.138-143
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• 1980

Hydrogel membranes were prepared by copolymerizing 2-hydroxyethyl methacrylate (HEMA) and N-vinyl-2-pyrrolidone (VP) in the presence of the solvent and the crosslinker tetraethyleneglycol dimethacrylate (TEGDMA). By changing the monomer composition and the crosslinker content, different membranes were synthesized. Using these membranes, relative permeabilities and distribution coefficients for amides including urea were measured. The water contents in membrane were also measured. On the basis of solute-membrane matrix interaction, the results were interpreted.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.555-560
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• 2023

Conventional aqueous amine-based CO₂ capture has a problem in that a large amount of renewable energy is required for CO₂ stripping and solvent regeneration in its industrial applications. This work proposes a water-lean absorbent that can reduce regeneration energy by lowering the water content in the absorbent with high absorption capacity for CO₂. To this purpose, this water-lean solvent introduced NMP (N-methyl-2-pyrrolidone), which has a higher physical solubility in CO₂ and a low specific heat capacity comparing to water, along with 3-methylaminopropylamine (MAPA), a diamine, into the absorbent. The circulating absorption capacity and absorption rate for CO₂ of this water-lean solvent were measured using a packed tower. When NMP was added to the absorbent, the absorption rate was improved. In the case of the absorbent containing 2.5M MAPA was used, the maximum circulating absorption capacity was obtained when 10 wt% of NMP was included in absorbent. The overall mass transfer coefficient increased as the concentration of NMP increased. However, at loading values higher than 0.5, the increment in mass transfer coefficient decreased as the concentration of NMP increased. When the lean loading value is low, the mass transfer resistance due to viscosity of the absorbent is low, so the overall mass transfer coefficient increases with the addition of NMP. However, as the lean loading value increases, the viscosity of the absorbent increases, and the diffusivity of CO₂ and MAPA decreases, resulting in sharply decreasing of the overall mass transfer coefficient.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.761-765
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• 2010

Poly (N,N-dimethylacrylamide) is very useful in various fields due to its remarkable properties, such as water solubility and biocompatibility. This study used N,N-dimethylacrylamide with the cross-linker EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), NVP (N-vinyl-2-pyrrolidone) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Measurement of the physical properties of the copolymerized polymer showed that the water content was 36 - 42%, refractive index was 1.433 - 1.426 and visible ray transmittance 90 - 91% while the oxygen permeability showed a distribution between 13.1 and $21.29{\times}10^{-11}(cm^2/sec)$ ($mlO_2/mL{\times}mmHg$). The measurement showed that the increased amount of oxygen permeability of the copolymer measured using the polarographic method range between 11.0% and 80.5%. Based on the results of this study, the produced copolymer is suitable for use as a material to high oxygen permeability hydrogel lenses.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.99-104
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• 2010

Platinum nanoparticles were added to a mixture of HEMA (2-hydroxyethyl methacrylate), NVP (N-vinyl pyrrolidone) and MMA (methyl methacrylate) in a mould at various concentrations. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for 40 min, $80^{\circ}C$ for 40 min, and $100^{\circ}C$ for 40 min, respectively. The physical properties of contact lens were then measured. The oxygen transmissibility of $9{\sim}15{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 34.22~35.52%, refractive index of 1.432~1.435, visible transmittance of 88.3~91.2% and tensile strength of 0.141~0.152 kgf were obtained. The addition of platinum nanoparticles to the polymer allowed the contact lens to have various colors without artificial coloring agents. The polymer materials satisfied the physical properties required to produce contact lenses, making the material suitable to be applied as a functional material for ophthalmological purposes.

• Journal of Veterinary Clinics
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• v.23 no.4
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• pp.400-404
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• 2006

This study demonstrates the anti-arthritic effect of topical application of ketoprofen gel containing N-methyl-2-pyrrolidone (NMP) in adjuvant arthritis therapy. Adjuvant arthritis was induced by a single injection of Freund's complete adjuvant (FCA). Mature female Sprague-Dawley rats were designated to 3 groups such as control group, K10 group (ketoprofen 10 mg/rat), and NK10 group (ketoprofen 10 mg/rat containing NMP). The anti-arthritic activity of ketoprofen containing NMP was tested not only as to its capability to suppress the inflammatory edema, but also bone damage (X-ray score and regional bone uptake) of the hind paw in arthritis-induced rats. These results showed a higher efficacy of ketoprofen containing NMP than ketoprofen treatment in the adjuvant-induced arthritis. Ketoprofen containing NMP has good intrinsic characteristics for formulation in an efficacious anti-inflammatory topical application.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.228-233
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• 2010

Recently, nanoparticles of gold and silver has been applied to various fields due to antimicrobial property. This study added Ag and Au nanoparticles in HEMA (2-hydroxyethylmethacrylate), NVP (N-vinyl pyrrolidone) and MMA (methylmethacrylate) and copolymerized the solution by heating at $70^{\circ}C$ for 40 minutes, $80^{\circ}C$ for 40 minutes, and finally, $100^{\circ}C$ for 40 minutes. Using the polymer produced through the copolymerization process, and measured the physical characteristics which showed water content of 28.43% ~ 35.27%, refractive index of 1.429 ~ 1.440, visible transmittance of 79.2% ~ 86.5% and tensile strength of 0.125 kgf ~ 0.201 kgf. We judged that we made the copolymer with antimicrobial and physical properties which is suitable for conventional contact lens.

• Clean Technology
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• v.20 no.2
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• pp.154-159
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• 2014

In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dimethyl sulfoxide (DMSO) solvent on behalf of N-methyl-2-pyrrolidone (NMP). XRD analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads synthesized by DMSO was about 4 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The maximum adsorption capacity obtained from Langmuir model was 21.31 mg/g. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. It was considered that the internal diffusion was the rate controlling step.

• Restorative Dentistry and Endodontics
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• v.42 no.4
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• pp.290-300
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• 2017

Objectives: This study investigated the removal efficacy and cytotoxicity of a newly developed calcium hydroxide paste (cleaniCal, Maruchi) using N-2-methyl-pyrrolidone (NMP) as a vehicle in comparison with ApexCal (Ivoclar Vivadent) and Calcipex II (Nishika), which use different vehicles such as polyethylene glycol and propylene glycol, respectively. Materials and Methods: Thirty maxillary premolars with oval-shaped canals were divided into 3 groups and the teeth were filled with one of the pastes. After removal of the paste, micro-computed tomographic (${\mu}$-CT) imaging was obtained to assess the volume of residual paste in the root canal of each tooth. The teeth were then split longitudinally and the area of the paste-coated surface was evaluated by stereomicroscopy. The cytotoxicity of each product was assessed using an agar overlay assay. The effect of each vehicle on cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The data were analyzed using one-way analysis of variance and Tukey's tests to detect any significance (p < 0.05). Results: In the ${\mu}$-CT and stereomicroscopic analysis, cleaniCal exhibited less remnants of medicament than ApexCal and Calcipex. cleaniCal showed a higher cytotoxicity than the other pastes in the agar overlay assay. Furthermore, NMP exhibited lower cell viability compared to the other vehicles. Conclusions: cleaniCal showed better removal efficacy compared to the other products. However, clinicians should be aware of the higher cytotoxicity of the NMP-based material and consider its possible adverse effects on periradicular tissue when it is overfilled.

• Journal of the Korean Chemical Society
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• v.62 no.1
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• pp.30-35
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• 2018

The purpose of this study was to decrease the protein adsorption and improve the function of the hydrophobic acrylic Intraocular lens(IOL). Hydrophobic acrylic intraocular lenses were prepared by using ethyleneglycol phenyletheracrylate (EGPEA), styrene and 2-hydroxyethyl methacrylate (HEMA). Polyvinyl pyrrolidone (PVP) and 2-methacryloyloxyethyl phosphorylcholine (MPC) were used as additives. Water contents, wettability, light transmittance and protein adsorption amount were measured to evaluate the physical properties of the intraocular lens. The water content and wettability of all samples containing additives were increased and the amount of protein adsorption decreased. In particular, samples containing MPC showed a further decrease in protein adsorption. The hydrophobic acrylic intraocular lens with PVP and MPC was found to improve the function of the intraocular lens by reducing the protein adsorption while having basic physical properties.