• 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.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1869-1874
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• 2010

By reducing PVP with $H_2NOH$.HCl and NaOH 2:2:1 mass ratios in aqueous ethanol, poly-N-vinyl pyrrolidone oxime [PVPO] was prepared with 92% yield. Applying the sol-gel concept, orthosilicic acid [OSA] was made by hydrolyzing TEOS with ethanol in 1:0.5 molar ratios using 1 N KOH aqueous solution as a catalyst. The OSA + PVPO + $_L$-Valine ($\alpha$-amino acid) were mixed with pure ethanolic medium in 1:2:2 mass ratios and refluxed at $78^{\circ}C$ and 6 pH for 6.5 h. A white residue of poly-N-vinyl pyrrolidone oximo-L-valyl-siliconate [POVS] appeared after 5 h. The heating of reaction mixture was stopped and the contents were brought to NTP. The residue formation of POVS was intensified with lowering a temperature and completely solidified within 5 h, was filtered using a vacuum pump with Whatmann filter paper no. 42. The residue of POVS was washed several times with 20% aqueous cold ethanolic solution and dried in vacuum chamber at $25^{\circ}C$ for 24 h. The MP was noted above $350^{\circ}C$. Structural and internal morphology were analyzed with IR and $^1H$-NMR, and SEM respectively. A drug loading and transporting ability of the POVS in water and at pH = 5 and 8 was determined chromatographically.

• Clean Technology
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• v.18 no.4
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• pp.347-354
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• 2012

In this study, simulation works have been performed for the $CO_2$ removal process contained in the DME production process using NMP (N-methyl-2-pyrrolidone) as a solvent. PRO/II with PROVISION release 9.1 at Invensys was used as a chemical process simulator and NRTL activity coefficient model with Henry's law option and Soave-Redlich-Kwong equation of state were used for thermodynamic models. For the determination of the binary interaction parameters in NRTL model, regression works have been performed to match the experimental thermodynamic data. Optimal feed tray location which minimizes the reboiler heat duty was determined.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2319-2323
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• 2007

Introduction of a difluoromethylene group into organic compounds has been observed to impart them with positive properties, as viewed by a wide range of industries. Here, synthesis of 3,3-difluoro-2-pyrrolidone derivatives (7) was accomplished by the reaction of ethyl 2,2-difluoro-4-iodo-4-(trimethylsilyl) butanolate (4) with primary amines followed by desilylation. The key intermediate (4) was prepared from the addition reaction of trimethylvinylsilane (3) to ethyl difluoroiodoacetate (2) in the presence of Cu(0). Ethyl difluoroiodoacetate (2) was prepared starting from ethyl bromodifluoroacetate (1) via Reformatsky-type reaction.

• Clean Technology
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• v.14 no.4
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• pp.242-247
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• 2008

Poly(N-vinyl-2-pyrrolidone) (PVP) has been used as biocompatible and biodegradable polymer in cosmetics, pharmaceuticals and electronics. Micro-particles of PVP were produced using an aerosol solvent extraction system (ASES). Dichloromethane (DCM) and supercritical carbon dioxide were used as solvent and antisolvent, respectively. The mean diameter of the obtained polymer particles ranged from 0.184 to $0.249\;{\mu}m$. The relationship between particle size and initial drop size was also considered.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.155-166
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• 1980

3-(N-Carbonylpyrrolidone)-propanoic acid potassium-salt and 3-(N-carbonylpyrrolidone)propenoic acid potassium-salt were synthesized by the reaction of 2-pyrrolidone potassium-salt with succinic anhydride and maleic anhydride in acetone and in acetone and in benzene. The anionic polymerization of 2-pyrrolidone with 3-(N-carbonylpyrrolidone)-propanoic acid potassium-salt or 3-(N-carbonylpyrrolidone)-propenoic acid potassium-salt as an initiator and potassium hydroxide as a catalyst was studied. It was found that 2.0 and 1.0 mole %, concentration of catalyst and initiator, and temperature of $50^{\circ}C$ was the optimum condition obtaining highest conversion and viscosity of polymer. The inherent viscosity of nylon 4 was measured to be 1.2 dl/g and 2.3 dl/g.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2584-2592
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• 2011

Nickel nanoparticle-poly(N-vinyl-2-pyrrolidone)/$TiO_2-ZrO_2$ composite (Ni-PVP/$TiO_2-ZrO_2$) was prepared by in situ polymerization method. The physical and chemical properties of Ni-PVP/$TiO_2-ZrO_2$ were investigated by XRD, FT-IR, BET, TGA, SEM and TEM techniques. The catalytic performance of this novel heterogeneous catalyst was determined for the Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid in the presence of methanol-water mixture as solvent. The effects of reaction temperature, the amount of catalyst, amount of support, solvent, and amount of metal for the synthesis of Ni-PVP/$TiO_2-ZrO_2$, were investigated as well as recyclability of the heterogeneous composite. The catalyst used for this synthetically useful transformation showed considerable level of reusability besides very good activity.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.167-174
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• 1980

Anionic polymerization of 2-pyrrolidone was carried out via PPBC/KOH catalysis. The effects of PPBC/KOH mole ratio, KOH concentration and temperature on polymerization have been investigated. It was observed that the highest rate of polymerization and maximum conversion were obtained when PPBC/KOH mole ratio was around 0.5. The maximum conversion and the highest viscosity were obtained when the concentration of KOH was 2 mole percent. It was also found that while the rate of polymerization at $50^{\circ}C$ was higher than at $30^{\circ}C$ in the initial stage of polymerization, the conversion and viscosity were decreased as polymerization time was extended. The rate constant $(k_p)$ of polymerization was determined by least square method; the values of $k_p$ obtained were $22.4\;l/mole{\cdot}hr\;at\;30^{\circ}C\;and\;191.9\;l/mole{\cdot}hr\;at\;50^{\circ}C$, respectively.

• Elastomers and Composites
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• v.14 no.4
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• pp.231-252
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• 1979

Polymerization of 2-pyrrolidone was carried out through anionic mechanism using $SO_2/KOH$ as catalyst. The effects of KOH concentration, $SO_2/KOH$ mole ratio and temperature on polymerization were investigated. The conversion and viscosity of polymers were measured at various polymerization conditions. It was observed that as the concentration of KOH was increased, equilibrium conversion was also increased. It was, however, found that after the concentration of KOH was reached above 8 mole percent, the equilibrium conversion was decreased. The highest rate of polymerization and maximum conversion were obtained when $SO_2/KOH$ mole ratio was around 0.5. It was also found that the rate of polymerization and the equilibrium conversion were higher at $50^{\circ}C$. than at $30^{\circ}C$. but the viscosity of polymer solution at $50^{\circ}C$. was not so high as expected. The rate constant, $K_p$ of polymerization, was determined by least square method: the value of $K_p$ was observed as 16 liter/mole hour at $50^{\circ}C$. and 2.6 liter/mole hour at $30^{\circ}C$., respectively. The mechanism of polymerization was also discussed.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.179-187
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• 1982

The copolymerization of N-acryloylpyrrolidone and acrylonitrile was performed in N,N'-dimethylformamide at 50$^{\circ}$C and monomer reactivity ratio was obtained by using IR working curve and Fineman and Ross equation. ($r_1$ = 0.43, $r_2$ = 1.56) It is found that resulting copolymer is good polymeric initiator for anionic graft copolymerization of 2-pyrrolidone. Graft copolymers with polybutylamide (nylon-4) grafts onto poly(NAP-Co-AN) backbone were synthesized and the various effects on the graft copolymerization of 2-pyrrolidone were examined. The rate constants ($K_p$) of graft anionic polymerization at 40 and 50$^{\circ}$C were 2.82${\times}$10 and 2.93${\times}$10(l/mole, min), respectively.