• Journal of the Korean Chemical Society
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• v.20 no.2
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• pp.158-165
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• 1976

The anionic polymerization of ${\varepsilon}$-caprolactam with N,N'-adipyl-bis-${\varepsilon}$-caprolactam as an initiator and potassium hydroxide as a catalyst was studied under various conditions.It was found that concentration of catalyst and initiator was 4.2 and 1.6 mole %, and polymerization temperature of 130$^{\circ}C$C, polymerization time of 1.5 hours was the optimum condition. The intrinsic viscosity and molecular weight of the obtained polymer was over 0.9 dl/g and 12,000. The polymerization was carried out in the presence of N-acyl-${\varepsilon}$-caprolactam as an initiator, it was observed that the reactivity of N,N'-adipyl-bis-${\varepsilon}$-caprolactam was greater than both of the N-benzoyl-${\varepsilon}$-caprolactam and N-acetyl-${\varepsilon}$-caprolactam. In general it was also observed that the intrinsic viscosity and yield of conversion was increased as an increasing of concentration of catalyst and initiator and also highly depend on temperature.

• Clean Technology
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• v.11 no.3
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• pp.117-122
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• 2005

N-vinyl caprolactam (NVCL), a kind of N-vinyl amide monomer, must be dissolved in continuous phase ($scCO_2$) for dispersion polymerization in supercritical carbon dioxide. Phase behavior of $CO_2$+NVCL is very important and necessary for determining initial polymerization condition and for monomer extraction from final polymer. There is the limitation of experimental method for obtaining pure properties of the monomer because of the possibility of polymerization. And N-methyl caprolactam (NMCL) is the useful solvent for the gas treating process. In the viewpoint of molecular thermodynamics, NVCL and NMCL have same functional group i.e. ${\varepsilon}$-caprolactam. In the case of NVCL, hydrogen of amide group is substituted with vinyl group and for NMCL, hydrogen of amide group is substituted with methyl group. We suggested modified group contribution method for this ${\varepsilon}$-caprolactam derivatives. This new group contribution parameter was applied to correlate $CO_2$ + N-vinyl caprolactam or N-methyl caprolactam system.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.375-380
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• 1987

D-$\alpha$-Amino-$\varepsilon$-carpolactam racemase (EC 5.1.1) and L-$\alpha$-amino-$\varepsilon$-caprolactam hydrolase (EC 3.5.2) were fractionated from cell-free extracts of Alcaligenes eutrophus A52 using ammonium sulfate precipitation and DEAE-cellulose ion exchange chromatography. It was made sure that D-$\alpha$-amino-$\varepsilon$-caprolactam was converted to L-$\alpha$-amino-$\varepsilon$-caprolactam by racemase, and then hydrolyzed into L-lysine by hydrolase in Alcaligenes eutrophus A52. For the conversion of D-$\alpha$-amino-$\varepsilon$-caprolactam into L-lysine by cell-free extracts of Alcaligenes eutrophus A52, the optimum temperature and pH were 6$0^{\circ}C$ and 8.5 respectively. The results showed that 0.5% D-$\alpha$-amino-$\varepsilon$-caprolactam was converted to L-lysine at 55$^{\circ}C$ for 10 hr with a conversion rate of 98% by cell-free extracts containing 3.1mg of protein.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.21-27
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• 1985

A bacterium which utilizes ${\varepsilon}$-caprolactam as a sole source of carbon and nitrogen was isolated from sludge of Shinchun river in Taegu and identified as Arthrobacter globiformis N-2-l. The growth medium for the optimum culture condition was composed of 0.4% ${\varepsilon}$-caprolactam, 0.02% $K_2HPO_4$, 0.05% $KH_2PO_4$, 0.02% $MgSO_4{\cdot}7H_2O$, 0.01% $FeCl_3{\cdot}6H_2O$ and 0.05% yeast extract. The optimum pH and temperature for growth were 7.0 and $30^{\circ}C$ respectively. The bacterial growth on the ${\varepsilon}$-caprolactam medium did not require any other organic nitrogen source such as yeast extract, although it was remarkably stimulated by the yeast extract. The bacteria utilized wide range of sugars and organic acids such as ${\alpha}$-ketoglutarate, adipate and P-hydroxybenzoate. The bacteria could use all kind of amino acids, ${\varepsilon}$-Caprolactam in the medium was consumed completely in the timecourse culture at $30^{\circ}C$ for 60 hr on the shaker by the bacteria. Decomposition product of ${\varepsilon}$-caprolactam by Arthrobacter globiformis N-2-1 was ${\varepsilon}$-aminocaproic acid.

• Fibers and Polymers
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• v.7 no.2
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• pp.112-116
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• 2006

Caprolactam is the most important raw material for making Nylon 6 fibers and its quality directly determines the quality of Nylon. So it is necessary to study the techniques and methods to remove the colorful impurities from caprolactam. In this paper, the decolorization of caprolactam aqueous solution by anion exchange resins was studied and the decoloring abilities of five commercial resins were investigated. The regeneration of the resins was also studied, too. This study shows that the resin AMTX202 have excellent decoloring ability in the column experiment and that the decoloring efficiency is correlated with the volume of resins packed and is slightly affected by the flow rate and regenerating times. The fact that the resins can be regenerated and reused without affecting the efficiency of decolorization will decrease the cost of the treatment and operation in the industry. The adsorption of colored compounds with anion exchange resins in the packed columns seems to be technically feasible.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.369-374
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• 1987

A bacterium which grows on D-$\alpha$-Amino-$\varepsilon$-Caprolactam as sole carbon, energy and nitrogen source was isolated from the sludge of industrial areas in Taegu, and identified as Alcaligenes eutrophus. The optimum pH, temperature and concentration of D-$\alpha$-Amino-$\varepsilon$-Caprolactam for the growth were 6.0, 3$0^{\circ}C$ and 0.2% respectively. The bacteria could utilize glucose and fructose as a carbon source, and utilize ammonium chloride, ammonium nitrate, ammonium sulfate and sodium nitrate as a nitrogen source, and utilize L-Iysine and L-glutamate as a carbon and nitrogen source. It was found with thin layer chromatography and polarimeter that D-$\alpha$-Amino-$\varepsilon$-Caprolactam was converted to L-Iysine by the cell-free extracts of Alcaligenes eutrophus A52.

• Journal of the Korean Chemical Society
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• v.21 no.2
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• pp.132-138
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• 1977

Anionic polymerization of ${\varepsilon}$-caprolactam via $SO_2$/KOH catalysis was attempted in order to find an optimal reaction condition and physical properties of the polymers. The yield of conversion was relatively low at low temperature and high at high temperature between $150^{\circ}C\;to\;180^{\circ}C$ regardless of $SO_2$/KOH mole ratio in polymerization of ${\varepsilon}$-caprolactam.The inherent viscosity of nylon 6 obtained via $SO_2$/KOH catalysis was 1.2∼2.7. The kinetic equation for the $SO_2$/KOH catalyzed polymerization has been derived and experimentally verified.

• Journal of the Korean Chemical Society
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• v.21 no.6
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• pp.440-444
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• 1977

The anionic polymerization of ${\varepsilon}$-caprolactam via $CS_2$/KOH catalysis was carried out under various conditions. The inherent viscosity of the polymers and percent conversion of the polymers were determined. It was observed that the percent conversion was increased as an increasing concentration of catalyst and initiator. The percent conversion was relatively low at low temperature and the highest percent conversion was obtained at temperature between $130^{\circ}C,\;to\;155^{\circ}C$ with any $CS_2$/KOH mole ratio.

• Journal of the Korean Chemical Society
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• v.20 no.6
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• pp.525-532
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• 1976

Anionic polymerization of 2-pyrrolidone and ${\varepsilon}$-Caprolactam via $CO_2/KOH catalysis was attempted in order to find reaction condition and physical properties of polymers. In case of polymerization of 2-pyrrolidone, the yield of conversion was increased when the concentration of potassium hydroxide was reached above 8 mole percent. The optimum of CO_2/KOH$ mole ratio was 0.45. It was also found that the polymerization was taking place at moderate temperature which was around $50^{\circ}C$. With regard to polymerization of-caprolactam, the yield of conversion was relatively low at $80^{\circ}C$ to $90^{\circ}C$and higher yield of conversion was obtained at higher temperature between $150^{\circ}C$ to $180^{\circ}C$ regardless of $CO_2/KOH mole ratio. The inherent viscosity of nylon 4 and nylon 6 which was made via CO_2/KOH$ catalysis was measured. The observed inherent viscosity was between 2.0 to 5.0.

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.909-914
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• 1996

In this research [RCOOH]-$\varepsilon$-Caprolactam-Montmorillonite was synthesized by reaction between Na-Mont-morillonite (10-Carboxy-n-decyl)dimethylethylammonium (=RCCOH) ion and $\varepsilon$-Caprolactame-Motmorillonite ob-tained was 3.62$\AA$ After heat treatment of this intercalations complex at 37$^{\circ}C$ in high vacuum for 12 h 24 h, 40 h and 90 h the basal spacing was reduced to 35.8$\AA$, 34.2, 17.5 $\AA$ and 16.6$\AA$ respectively. The calculated amount of free $\varepsilon$-caprolactame included int he intercaltions complex and that of $\varepsilon$-caprolactame which is interca-lated into the interlayer space of montomorillonite and still remained after heat treatment are 4.6~4.9 and 0.5 molecules per unite cell of montmorillonite respectively.