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Sample records for caprolactam

  1. Caprolactam Tightens

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Caprolactam is an important organic chemical raw material. It is mainly used to produce nylon 6 engineering plastics and nylon 6 fibers. In addition, caprolactam can also he used to produce antiplatelet drug 6-aminocaproic acid and laurocapram.

  2. Purification of caprolactam from recycled nylon

    Science.gov (United States)

    Moens, Luc

    1999-01-01

    A method of removing 1,11-diamino-6-undecanone from the pyrolysis product of nylon comprising: a) pyrolyzing nylon-6 to form a pyrolyzate containing a caprolactam mixture; b) dissolving the caprolactam mixture in a solvent to form a solution; c) passing carbon dioxide gas through the solution to form a precipitate; d) removing the precipitate from the solution; and e) recovering the purified caprolactam from the solution.

  3. Recovery of Caprolactam from Waste Water in Caprolactam Production Using Pulsed—sieve—plate Extraction column

    Institute of Scientific and Technical Information of China (English)

    LIUJiangqing; XIEFangyou; 等

    2002-01-01

    Recovery of caprolactam from waste water of caprolactam production factory was investigated using benzence as solvent in a small-scale pulsed-sieve-plate column.First,liquid-liquid equilibrium (LLE) deta were measured,including water-caprolactam-benzene system at low caprolactam concentrations,and waste water-benzene system.Then,the operating regions and mass transfer of the pulsed-sieve-plate column were measured.Finally,the overall apparent heights of a transfer unit based on continuous phase are correlated in terms of the column operation variables.

  4. Caprolactam production by direct solar flux

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, J.; Wong, E.H.S.; Mathur, V.K. (Univ. of New Hampshire, Durham (United States))

    1991-01-01

    The use of solar energy for the photonitrozation of cyclohexane for the production of cyclohexanone oxime hydrochloride, an intermediate for the manufacture of caprolactam, is discussed. Experimental results show the technical feasibility of such a reaction in the presence of radiation of wavelength 350-550 nm simulating sunlight.

  5. Thermodynamic Properties of Caprolactam Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    JIANG Lu; BAI Liguang; ZHU Jiqin; CHEN Biaohua

    2013-01-01

    A series of caprolactam ionic liquids (ILs) containing incorporated halide anions were synthesized.Their physical properties,such as melting points,heats of fusion and heat capacities,were measured by differential scanning calorimeter (DSC).The results indicate that these ionic liquids exhibit proper melting points,high value of heats of fusion,and satisfying heat capacities which are suitable for thermal energy storage applications.

  6. Selection and evaluation of alternative solvents for caprolactam extraction

    NARCIS (Netherlands)

    Delden, van Mathijs L.; Kuipers, Norbert J.M.; Haan, de André B.

    2006-01-01

    Because of the strict legislation for currently applied solvents in the industrial extraction of caprolactam, being benzene, toluene and chlorinated hydrocarbons, a need exists for alternative, environmentally benign solvents. An experimental screening procedure consisting of several steps was used

  7. Benzylic oxidation catalyzed by dirhodium(II,III) caprolactamate.

    Science.gov (United States)

    Catino, Arthur J; Nichols, Jason M; Choi, Hojae; Gottipamula, Sidhartha; Doyle, Michael P

    2005-11-10

    [reaction: see text] Dirhodium caprolactamate [Rh2(cap)4] is an effective catalyst for benzylic oxidation with tert-butyl hydroperoxide (TBHP) under mild conditions. Sodium bicarbonate is the optimal base additive for substrate conversion. Benzylic carbonyl compounds are readily obtained, and a formal synthesis of palmarumycin CP2 using this methodology is described.

  8. Uptake of caprolactam and its influence on growth and oxygen production of Desmodesmus quadricauda algae.

    Science.gov (United States)

    Kalinová, Jana Pexová; Tříska, Jan; Vrchotová, Naděžda; Novák, Jan

    2016-06-01

    The consumption of polyamides produced from caprolactam is increasing continuously, and for that reason the danger of environmental contamination by this lactam is also rising. This study's aim was to evaluate the influence of caprolactam on the growth and oxygen production of the green alga Desmodesmus quadricauda and on caprolactam uptake by this alga. The presence of caprolactam in water was observed to cause the algae significantly to increase its oxygen production. Caprolactam concentration of 5,000 mg/L stopped algae growth after 6 days and influenced coenobia structure (seen as disappearance of pyrenoids, deformation of cells) but did not decrease the number of cells in the coenobia. Caprolactam uptake is probably passive but relatively rapid. Maximum concentration in the algae was reached after 18-24 h.

  9. Breakthroughs in Follow-uD Development of Caprolactam Package Technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ After five-year-long joint tackling of key problems undertaken by experts of the SINOPEC Research Institute of Petroleum Processing (RIPP) and research workers of the Caprolactam Division of Baling Petrochemical Company the project "Study on new technology for gas phase rearrangement of caprolactam" following solving the problems related with oxime vaporization and catalysts has fulfilled the contract requirements for all technical indicators.It means that the follow-up development of package technology for caprolactam manufacture has made great strides to lay a solid foundation for creating and adopting the package caprolactam technology that features independent intellectual property rights.

  10. Impurity Distribution Behavior in Caprolactam Extraction with Environmentally Benign Mixed Solvents

    NARCIS (Netherlands)

    Delden, van M.L.; Drumm, C.; Kuipers, N.J.M.; Haan, de A.B.

    2006-01-01

    In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model impur

  11. Tensile Properties of Poly (N-vinyl caprolactam) Gels

    Science.gov (United States)

    Morgret, Leslie D.; Hinkley, Jeffrey A.

    2004-01-01

    N-vinyl caprolactam was copolymerized with ethylene glycol dimethacrylate using a free-radical initiator in alcohol/water solution. The resulting gels were thermally-responsive in water, undergoing an approximate fivefold reversible volume shrinkage between room temperature and ca. 50 C. Tensile testing showed that the stress-strain behavior was qualitatively different in the collapsed state above the temperature-induced transition. At the higher temperature, gels were stiffer, more ductile, and showed greater time dependence. Implications for the design of gel actuators are briefly discussed.

  12. 苯或甲苯萃取己内酰胺和甲基己内酰胺分配系数的测定和预测%Distribution Coefficient of Caprolactam and Methyl Caprolactam Using Benzene or Toluene as Extractants: Experiments and Prediction

    Institute of Scientific and Technical Information of China (English)

    龚行楚; 吕阳成; 骆广生

    2007-01-01

    To get high purity caprolactam is a challenging task in the chemical fiber industry. To date, reports on the prediction of the distribution of caprolactam and its derivative chemicals have been few. In this study, the extraction of caprolactam with toluene as the extractant and N-methyl caprolactam with benzene and toluene as the extractants has been carried out. By defining new UNIFAC groups and calibrating related interaction parameters, a UNIFAC method was introduced to predict the equilibrium concentration of caprolactam and methyl caprolactam in toluene or benzene extraction processes. The calculated results fit very well with the experimental data. Using the UNIFAC model, the selectivity of extractants can be predicted.

  13. Catalytic conversion of γ-valerolactone to ε-caprolactam: towards nylon from renewable feedstock.

    Science.gov (United States)

    Raoufmoghaddam, Saeed; Rood, Marcus T M; Buijze, Florine K W; Drent, Eite; Bouwman, Elisabeth

    2014-07-01

    The conversion of γ-valerolactone (GVL) in three atom-efficient steps to the important polymer precursor ε-caprolactam is reported. The bio-based GVL can be converted to a mixture of isomeric methyl pentenoates (MP) via trans-esterification with methanol with 94% yield (ratio of 3-MP/4-MP=3:1); subsequent aminolysis with ammonia leads to a mixture of pentenamides (PA) almost quantitatively (99% conversion). The resulting pentenamides are ultimately converted into ε-caprolactam via a rhodium-catalyzed intramolecular hydroamidomethylation reaction, comprising an initial hydroformylation of the alkene moiety of PA and subsequent ring-closing reductive amidation of the resulting aldehyde with the amide functionality. A promising yield of caprolactam of about 90% can be obtained with a Rh/xantphos catalyst system in a two-stage hydroformylation-reductive amidation using pure 4-PA as feedstock. The use of 3-PA as a substrate not only results in a significantly lower regioselectivity for the 7-membered lactam, but also in the formation of high amounts of valeramide (VA). Consequently, a best overall yield of caprolactam of nearly 40% could be demonstrated with a Rh/POP-xantphos [POP-xantphos=4,5-bis(2,8-dimethyl-10-phenoxaphosphino)-9,9,-dimethylxanthene] catalyst system based on the 3:1 mixture of 3-PA/4-PA directly obtainable from GVL.

  14. Impact modification of poly(caprolactam) by copolymerization with a low molecular weight polybutadiene

    NARCIS (Netherlands)

    Borggreve, R.J.M.; Gaymans, R.J.

    1988-01-01

    Caprolactam and a reactive, low molecular weight polybutadiene were polymerized in an autoclave, followed by post-condensation in the solid state. The rubber concentration was varied (0–30 wt%). The morphology of the reaction products was studied by transmission electron microscopy. In the materials

  15. Cationic Ring Opening polymerization of ε-caprolactam by a Montmorillonite Clay Catalyst

    Directory of Open Access Journals (Sweden)

    Djamal Eddine Kherroub

    2014-03-01

    Full Text Available The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H+ was reported. Maghnite-H+ is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H+ proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl–oxygen bond scission rather than the break of alkyl–oxygen bond. © 2014 BCREC UNDIP. All rights reservedSubmitted: 3rd October 2013; Revised: 28th February 2014; Accepted: 1st March 2014[How to Cite: Kherroub, D.E., Belbachir, M., Lamouri, S. (2014. Cationic Ring Opening Polymeriza-tion of ε-caprolactam by a Montmorillonite Clay Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 74-79. (doi:10.9767/bcrec.9.1.5555.74-80][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5555.74-80

  16. One-step Synthesis of ε-Caprolactam by the Liquid Phase Nitrosation of Cyciohexane over the Catalysts Containing CH3COO-or-COOH

    Institute of Scientific and Technical Information of China (English)

    MAO Li-qiu; CHEN Lei; WU Bo-hua; YIN Du-lin; YOU Kui-yi; LIU Ping-le; LUO He-an

    2008-01-01

    @@ ε-Caprolactam(CL or CPL) is one of the most important intermediates used in polymer industry for the production of several million tons of nylon-6 every year[1].All current commercial processes for the production of caprolactam are based on either benzene or toluene[2].

  17. A biological/chemical process for reduced waste and energy consumption: caprolactam production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    A biological/chemical process for converting cyclohexane into caprolactam was investigated: microorganisms in a bioreactor would be used to convert cyclohexane into caprolactone followed by chemical synthesis of caprolactam using ammonia. Four microorganisms were isolated from natural soil and water, that can utilize cyclohexane as a sole source of C and energy for growth. They were shown to have the correct metabolic intermediates and enzymes to convert cyclohexane into cyclohexanol, cyclohexanone, and caprolactone. Genetic techniques to create and select for caprolactone hydrolase negative-mutants were developed; those are used to convert cyclohexane into caprolactone but, because of the block, are unable to metabolize the caprolactone further. Because of a new nylon carpet reycle process and the long time frame for a totally new bioprocess, a limited study was done to evaluate whether a simplified bioprocess to convert cyclohexanol into cyclohexanone or caprolactone was feasible; growth rates and key enzyme levels were measured in a collection of microorganisms that metabolize cyclohexanol to determine if the bioactivity is high enough to support an economical cyclohexanol bioprocess. Although these microorganisms had sufficient bioactivity, they could tolerate only low levels (<1%) of cyclohexanol and thus are not suitable for developing a cost effective bioprocess because of the high cost of dilute product recovery.

  18. Reusable task-specific ionic liquids for a clean ε-caprolactam synthesis under mild conditions.

    Science.gov (United States)

    Turgis, Raphaël; Estager, Julien; Draye, Micheline; Ragaini, Vittorio; Bonrath, Werner; Lévêque, Jean-Marc

    2010-12-17

    Brønsted-acidic ionic liquids that bear a sulfonic acid group, known as Forbes acids, show a good catalytic activity for the Beckmann rearrangement, used to prepare ε-caprolactam, which is a precursor of Nylon 6. The activity essentially stems from the acidity of the sulfonic acid group. Although these task specific ionic liquids suffer from a high viscosity, this drawback can be circumvented at higher temperatures. A combination of the hydrogen sulfate anion and the sulfonic acid group of the cation is needed to obtain the rearrangement product rapidly under mild conditions. When using an excess of ionic liquid, we postulate that the internal pressure of the ionic medium, generated by the high viscosity and the high number of hydrogen-bonds, is strong enough to contribute to a decrease of the thermodynamic barrier. In accordance with the "Principles of Green Chemistry," we have developed a synthesis of ε-caprolactam that requires no additional chemicals except cyclohexanone oxime and the reusable TSIL.

  19. Interlaboratory Study on Caprolactam Test for Food-Contact Nylon Products.

    Science.gov (United States)

    Watanabe, Kazunari; Mutsuga, Motoh; Abe, Takashi; Abe, Tomoyuki; Abe, Yutaka; Ohsaka, Ikue; Ohno, Haruka; Ohno, Hiroyuki; Ohno, Yuichiro; Ozaki, Asako; Kakihara, Yoshiteru; Kobayashi, Hisashi; Kondo, Takahide; Shibata, Hiroshi; Shirono, Katsuhiro; Sekido, Haruko; Sonobe, Hironori; Takasaka, Noriko; Tajima, Yoshiyasu; Tanaka, Aoi; Tanaka, Hideyuki; Nakanishi, Toru; Nomura, Chie; Haneishi, Nahoko; Hayakawa, Masato; Hikida, Akinori; Miura, Toshihiko; Yamaguchi, Miku; Sato, Kyoko; Akiyama, Hiroshi

    2016-01-01

    The Japanese Food Sanitation Law sets a limit on the migration level of caprolactam for food-contacting nylon products. Here, we carried out an interlaboratory study in twenty laboratories to evaluate the performance of the official GC-FID test method and a GC-MS method as an alternative test method to the official method. Each laboratory quantified caprolactam in three test solutions in 20% ethanol as blind duplicates using GC-FID or GC-MS. The official method (GC-FID with absolute calibration) gave trueness, repeatability (RSDr) and reproducibility (RSDr) values of 96-97%, 3.3-5.4% and 4.0-6.7%, respectively. These values met the target criteria (trueness: 80-110%, RSDr: 10%, RSDr: 25%). The performance of the method was further improved by the introduction of heptalactam as an internal standard. As for GC-MS method, some values of the RSDr exceeded 10% when absolute calibration was used. However, when an internal standard was introduced, the trueness, RSDr and RSDr of GC-MS method were all acceptable at 94-96%, 2.0-4.4% and 7.0-9.4%, respectively. Therefore, GC-MS with an internal standard is available as an alternative test method to the official method.

  20. Terahertz Absorption Spectroscopy of Benzamide, Acrylamide, Caprolactam, Salicylamide, and Sulfanilamide in the Solid State

    Directory of Open Access Journals (Sweden)

    Ye Jiang

    2014-01-01

    Full Text Available Terahertz (THz absorption spectra of the similarly structured molecules with amide groups including benzamide, acrylamide, caprolactam, salicylamide, and sulfanilamide in the solid phase at room temperature and 7.8 K for salicylamide are reported and compared to infrared vibrational spectral calculations using density functional theory. The results of THz absorption spectra show that the molecules have characteristic bands in the region of 0.2–2.6 THz (~7–87 cm−1. THz technique can be used to distinguish different molecules with amide groups. In the THz region benzamide has three bands at 0.83, 1.63, and 1.73 THz; the bands are located at 1.44 and 2.00 THz for acrylamide; the bands at 1.24, 1.66 and 2.12 THz are observed for caprolactam. The absorption bands are located at 1.44, 1.63, and 2.39 THz at room temperature, and at 1.22, 1.46, 1.66, and 2.41 THz at low temperature for salicylamide. The bands at 1.63, 1.78, 2.00, and 2.20 THz appear for sulfanilamide. These bands in the THz region may be related to torsion, rocking, wagging, and other modes of different groups in the molecules.

  1. A novel approach for one-step forming ε-caprolactam from cyclohexane nitrozation catalyzed by transition metal salt

    Institute of Scientific and Technical Information of China (English)

    Li Qiu Mao; BO Hua Wu; Du Lin Yin; Kui Yi You; Ping Le Liu; He An Luo

    2007-01-01

    The nitrozation reaction of cyclohexane in one-step reaction to form ε-caprolactam has been studied using transition metal salt as catalysts in this work. The results indicated that the catalysts play an especially important role. This method is expected to be a novel way to synthesize other lactam by similar reaction. The possible mechanism was suggested.

  2. Green Caprolactam Production Technology%己内酰胺绿色生产技术

    Institute of Scientific and Technical Information of China (English)

    孙斌; 孟祥堃; 宗保宁

    2011-01-01

    Ideal of green chemistry is the reaction of "atom economy" and production of environment-friendly green products.This requires that every atom in the raw materials entry into the product,no waste and by-products are produced,and the poisonous and harmful materials are not used in the process.To practice the concept of green chemistry,Research Institute of Petroleum Processing have developed the green caprolactam production technology successfully and constructed a commercial unit which the productivity is to be 2×105 t/a.The innovation technology includes: single-vessel continuous slurry bed integration with titanium silicate zeolite for cyclohexanone ammonization,and amorphous alloy catalyst integration with magnetically stabilized bed for purification of caprolactam.Based on the commercial application,the investment of the caprolactam production plant has decreased 70%,the operation costs decreased 10%,the atom utilization increased from 60% to 90%,and there are waste-free essentially,respectively.The green caprolactam production technology has well practiced the green chemistry concepts and became a successful example of green chemistry.%绿色化学的理想是实现反应的"原子经济"性,生产环境友好的绿色产品,这就要求原料中的每一个原子进入产品,不产生废物和副产品,并采用无毒无害的原料、催化剂和溶剂。根据绿色化学的理念,中国石化石油化工科学研究院历经20年,开发成功己内酰胺绿色生产技术,建成20万t/a工业生产装置。这项技术包括:单釜连续淤浆床与钛硅分子筛集成用于环己酮氨肟化合成环己酮肟;非晶态合金催化剂与磁稳定床集成用于己内酰胺加氢精制。工业实施后,使装置投资下降70%、生产成本下降10%、原子利用率由60%提高到90%以上,三废排放是引进国外技术路线的1/200,产生了重大经济效益和社会效益。己内酰胺绿色生产技术的开发,践行了绿色化

  3. Beckmann rearrangement of cyclohexanone oxime to {epsilon}-caprolactam using a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Dahlhoff, G.; Hoelderich, W.F. [Technische Hochschule Aachen (Germany)

    1999-07-01

    The application of a fluidized bed reactor on the heterogeneously catalyzed Beckmann rearrangement of cyclohexanone oxime to {epsilon}-caprolactam is presented. For this purpose the classic industrial synthesis route is compared to the new route catalyzed by [B]-MFI zeolite which proved to be the most suitable. To prepare the use of the catalyst the thermodynamics were calculated showing that the residence time of the reactants are of great importance. A regeneration model was developed resulting in a mathematical equation for the regeneration time calculated to seven hours under oxidative conditions. A 40 day regeneration experiment demonstrated the excellent regeneration behaviour of the chosen catalyst showing no decrease in activity after 40 recycle treatments. Finally, the experiments in a constructed non circulating fluidized bed showed good yields and selectivities (99%/91%) completely comparable to the actual synthesis route but avoiding 4 t ammonia sulphate/t product. (orig.)

  4. Package Technology for Manufacture of Caprolactam Developed by SINOPEC Commands Internationally Leading Position

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ In October one of SINOPEC's ten core projects to be tackled- "Development of package technology for the 140kt/a caprolactam unit" had passed the technical appraisal organized by the SINOPEC Group.This package technology integrates new techniques relating to the production of cyclohexanone via oxidation of ethylene oxide,the production of cyclohexanone-oxime through ammoximation of cyclohexanone,the triple rearrangement of cyclohexanoneoxime,and the purification ofcaprolactam.The overall package technology has reached the internationally advanced level with independent intellectual property rights,and has filed or has been granted a lot of Chinese and overseas patents.This package technology has been successfully adopted in commercial scale at the Baling Petrochemical Company.

  5. Influence of cyclodextrin on the UCST- and LCST-behavior of poly(2-methacrylamido-caprolactam-co-(N,N-dimethylacrylamide

    Directory of Open Access Journals (Sweden)

    Alexander Burkhart

    2014-08-01

    Full Text Available The monomer 2-methacrylamido-caprolactam (4 was synthesized from methacryloyl chloride (3 and racemic α-amino-ε-caprolactam (2. Copolymerization of 4 with N,N-dimethylacrylamide (5 was carried out by a free-radical mechanism using 2,2’-azobis(2-methylpropionitrile (AIBN as an initiator. The new copolymers show a lower critical solution temperature (LCST in water and an upper critical solution temperature (UCST in ethanol, 1-propanol, and 1-butanol. The solubility properties of the copolymers can be influenced significantly by the addition of randomly methylated β-cyclodextrin (CD. The complexation of the copolymers with CD, was confirmed by the use of ROESY-NMR-spectroscopy.

  6. Design of a "green" one-step catalytic production of epsilon-caprolactam (precursor of nylon-6).

    Science.gov (United States)

    Thomas, John Meurig; Raja, Robert

    2005-09-27

    The ever-increasing industrial demand for nylon-6 (polycaprolactam) necessitates the development of environmentally benign methods of producing its precursor, epsilon-caprolactam, from cyclohexanone. It is currently manufactured in two popular double-step processes, each of which uses highly aggressive reagents, and each generates substantial quantities of largely unwanted ammonium sulfate as by-product. Here we describe a viable laboratory-scale, single-step, solvent-free process of producing epsilon-caprolactam using a family of designed bifunctional, heterogeneous, nanoporous catalysts containing isolated acidic and redox sites, which smoothly convert cyclohexanone to epsilon-caprolactam with selectivities in the range 65-78% in air and ammonia at 80 degrees C. The catalysts are microporous (pore diameter 7.3 A) aluminophosphates in which small fractions of the Al(III)O4(5-) and P(V)O4(3-) tetrahedra constituting the 4-connected open framework are replaced by Co(III)PO4(5-) and Si(IV)O4(4-) tetrahedra, which become the loci of the redox and acidic centers, respectively. The catalysts may be further optimized, and already may be so designed as to generate selectivities of approximately 80% for the intermediate oxime, formed from NH2OH, which is produced in situ within the pore system. The advantages of such designed heterogeneous catalysts, and their application to a range of other chemical conversions, are also adumbrated.

  7. Applicability of the theory of volume filling of micropores to adsorption of caprolactam from aqueous solutions with active carbons

    Energy Technology Data Exchange (ETDEWEB)

    Khodorov, E.I.; Kazakov, V.A.; Semerikova, V.V.; Surinova, S.I.

    1985-06-10

    The absence of a scientifically based method of selecting adsorbents in the extraction of organic substances from waste water and solution which would allow for their multicycle use in adsorption-desorption stages often prevents the introduction of adsorption technology into industrial practice. This paper demonstrates the possibility of calculating the adsorption equilibrium of highly soluble organic compounds with the theory of volume filling of micropores equations in consideration of the activities of the extracted component in the solution and the change in the partial affinity coefficient with the degree of filling of the adsorption volume on the example of extraction of caprolactam from aqueous solutions.

  8. Comparative Theoretical Study of the Ring-Opening Polymerization of Caprolactam vs Caprolactone Using QM/MM Methods

    Energy Technology Data Exchange (ETDEWEB)

    Elsasser, Brigitta M.; Schoenen, Iris; Fels, Gregor

    2013-06-07

    Candida antarctica lipase B (CALB) efficiently catalyzes the ring-opening polymerization of lactones to high molecular weight products in good yield. In contrast, an efficient enzymatic synthesis of polyamides has so far not been described in the literature. This obvious difference in enzyme catalysis is the subject of our comparative study of the initial steps of a CALB catalyzed ring-opening polymerization of ε- caprolactone and ε-caprolactam. We have applied docking tools to generate the reactant state complex and performed quantum mechanical/molecular mechanical (QM/MM) calculations at the density functional theory (DFT) PBE0 level of theory to simulate the acylation of Ser105 by the lactone and the lactam, respectively, via the corresponding first tetrahedral intermediates. We could identify a decisive difference in the accessibility of the two substrates in the ring-opening to the respective acyl enzyme complex as the attack of ε-caprolactam is hindered because of an energetically disfavored proton transfer during this part of the catalytic reaction while ε-caprolactone is perfectly processed along the widely accepted pathway using the catalytic triade of Ser105, His224, and Asp187. Since the generation of an acylated Ser105 species is the crucial step of the polymerization procedure, our results give an explanation for the unsatisfactory enzymatic polyamide formation and opens up new possibilities for targeted rational catalyst redesign in hope of an experimentally useful CALB catalyzed polyamide synthesis.

  9. Formation and Compatibilizing Effect of the Grafted Copolymer in the Reactive Blending of 2-Diethylsuccinate Containing Polyolefins With Poly-ε-caprolactam (Nylon-6)

    NARCIS (Netherlands)

    Passaglia, Elisa; Aglietto, Mauro; Ruggeri, Giacomo; Picchioni, Francesco

    1998-01-01

    The intermolecular reaction and its role in determining the partial compatibility between diethylsuccinate containing linear low-density polyethylene or ethylene propylene copolymer and poly-ε-caprolactam (PA6) has been investigated in the melt using a Brabender mixer. The reaction product has been

  10. 己内酰胺生产技术进展及项目投资分析%Caprolactam production technological prowess and project investment analysis

    Institute of Scientific and Technical Information of China (English)

    杨军; 冯美平

    2013-01-01

    The caprolactam production technologies were briefly introduced. The latest progress in caprolactam production technology was described in detail, including butadiene process, cyclohexene hydration, cyclohexanone oxime gas-phase Beckmann rearrangement, cyclohexanone oximation. The ammoximation process and hydroxylammonium phosphate ( HPO) process were compared and analyzed for caprolactam. It was pointed out that the ammoximation process had the characteristics of simple process, moderate conditions, low-level three wastes and low investment. The investment prospects of caprolactam projects were analyzed. It was put forward that SINOPEC should carefully conduct project evaluation in order to avoid risk while constructing a caprolactam project applying the cyclohexanone ammoximation process with the independent intellectual property or traditional cy-clohexane route.%简述了己内酰胺生产现状;详述了己内酰胺生产技术最新进展,包括丁二烯工艺、环己烯水合工艺、环己酮肟气相贝克曼重排新工艺、环己酮氨肟化工艺;对比剖析了己内酰胺氨肟化新工艺技术与HPO法技术,指出环己酮氨肟化新工艺具有流程简化,反应条件温和,三废少,投资少的特点;并对己内酰胺项目投资前景进行分析,提出中石化采用环己酮氨肟化法自主技术及环己烷法生产工艺路线新建己内酰胺项目并做好项目评估,规避项目风险.

  11. Design of a “green” one-step catalytic production of ε-caprolactam (precursor of nylon-6)

    Science.gov (United States)

    Thomas, John Meurig; Raja, Robert

    2005-01-01

    The ever-increasing industrial demand for nylon-6 (polycaprolactam) necessitates the development of environmentally benign methods of producing its precursor, ε-caprolactam, from cyclohexanone. It is currently manufactured in two popular double-step processes, each of which uses highly aggressive reagents, and each generates substantial quantities of largely unwanted ammonium sulfate as by-product. Here we describe a viable laboratory-scale, single-step, solvent-free process of producing ε-caprolactam using a family of designed bifunctional, heterogeneous, nanoporous catalysts containing isolated acidic and redox sites, which smoothly convert cyclohexanone to ε-caprolactam with selectivities in the range 65–78% in air and ammonia at 80°C. The catalysts are microporous (pore diameter 7.3 Å) aluminophosphates in which small fractions of the \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{Al}}^{{\\mathrm{III}}}{\\mathrm{O}}_{4}^{5-}\\end{equation*}\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{P}}^{{\\mathrm{V}}}{\\mathrm{O}}_{4}^{3-}\\end{equation*}\\end{document} tetrahedra constituting the 4-connected open framework are replaced by \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{Co}}^{{\\mathrm{III}}}{\\mathrm{PO}}_{4}^{5-}\\end{equation*}\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage

  12. Hydrogen bond driven chemical reactions: Beckmann rearrangement of cyclohexanone oxime into epsilon-caprolactam in supercritical water.

    Science.gov (United States)

    Boero, Mauro; Ikeshoji, Tamio; Liew, Chee Chin; Terakura, Kiyoyuki; Parrinello, Michele

    2004-05-26

    Recent experiments have shown that supercritical water (SCW) has the ability to accelerate and make selective synthetic organic reactions, thus replacing the common but environmentally harmful acid and basic catalysts. In an attempt to understand the intimate mechanism behind this observation, we analyze, via first-principles molecular dynamics, the Beckmann rearrangement of cyclohexanone oxime into epsilon-caprolactam in supercritical water, for which accurate experimental evidence has been reported. Differences in the wetting of the hydrophilic parts of the solute, enhanced by SCW, and the disrupted hydrogen bond network are shown to be crucial in triggering the reaction and in making it selective. Furthermore, the enhanced concentrations of H(+) in SCW play an important role in starting the reaction.

  13. Flame retardant polyamide 6 by in situ polymerization of ε-caprolactam in the presence of melamine derivatives

    Institute of Scientific and Technical Information of China (English)

    Zhi Yong Wu; Wei Xu; Jin Kui Xia; Yao Chi Liu; Qian Xin Wu; Wei Jian Xu

    2008-01-01

    An improved method for preparing melamine cyanurate (MCA)based flame retardant polyamide 6 (FRPA6)materials has been proposed.This processing method,i.e.,improved in situ polymerization,was used to synthesize flame retardant PA6.In situ formed MCA nanoparticles were supposed to be linked to PA6 chains in the ε-caprolactam hydrolytic polymerization system to obtain startype polymers for the first time.Through TEM photographs,it can be found that the in situ formed MCA nanoparticles with diametric size of less than 50 nm,are nanoscaled,highly uniformly dispersed in the PA6 matrix.Synthesized flame retardant PA6 have good fire performance which can achieve UL-94 V-0 rating at 1.6 mm thickness with the presence of 7.34 wt.% MCA in the matrix.

  14. A biological/chemical process for reduced waste and energy consumption, Caprolactam production: Phase 1, Select microorganisms and demonstrate feasibility. Final report

    Energy Technology Data Exchange (ETDEWEB)

    St.Martin, E.J.

    1995-08-01

    A novel biological/chemical process for converting cyclohexane into caprolactam was investigated. Microorganisms in a bioreactor would be used to convert cyclohexane into caprolactone followed by chemical synthesis of caprolactam using ammonia. The proposed bioprocess would be more energy efficient and reduce byproducts and wastes that are generated by the current chemical process. We have been successful in isolating from natural soil and water samples two microorganisms that can utilize cyclohexane as a sole source of carbon and energy for growth. These microorganisms were shown to have the correct metabolic intermediates and enzymes to convert cyclohexane into cyclohexanol, cyclohexanone and caprolactone. Genetic techniques to create and select for caprolactone hydrolase negative-mutants are being developed. These blocked-mutants will be used to convert cyclohexane into caprolactone but, because of the block, be unable to metabolize the caprolactone further and excrete it as a final end product.

  15. 新型己内酰胺萃取剂的筛选和评价%Selection and evaluation of a new extractant for caprolactam Extraction

    Institute of Scientific and Technical Information of China (English)

    龚行楚; 吕阳成; 李牧; 马雪峰; 倪前银; 骆广生

    2008-01-01

    Mixed solvent of 1-octanol and cyclohexane with 60% (by mass) 1-octanol content was selected as a new extractant for caprolactam extraction. Compared with benzene or toluene, the new extractant has larger extraction capacity and much lower toxicity. Although the extraction capacity of the new extractant is smaller than that of pure 1-octanol, 1-octanol solubility of the new extractant in aqueous phase is much smaller. Because of its physical properties of lower density, lower viscosity, and higher interfacial tension, the new extractant performed much better phase separation ability than pure 1-octanol. The new extractant showed certain selectivity when dealing with lactam oil. The mixed solvent of 1-octanol and cyclohexane with 60% (by mass) 1-octanol content is a promising extractant for caprolactam extraction.

  16. Investigation on the Cellulose Graft Copolymerization With Caprolactam%纤维素与己内酰胺接枝共聚改性研究

    Institute of Scientific and Technical Information of China (English)

    李政; 王鑫

    2014-01-01

    Cellulose is an important natural biodegradable polymer. The deficiency of cellulose can be improved by graft copolymerization with caprolactam. In this paper, dissolution property of cellulose in organic phase of DMAC/LiCl was discussed as well as the graft copolymerization reaction of cellulose and caprolactam, and grafted copolymer was characterized.%纤维素是一种重要的天然生物可降解聚合物,将纤维素与己内酰胺接枝共聚可以改性天然纤维素的不足。以纤维素为原料,讨论其在DMAC/LiCl体系有机相中溶解性质及与己内酰胺的接枝共聚反应,并对接枝物进行了表征测试。

  17. Utilization of SO/sub 2/ gas of boiler flue gas in the epsilon-caprolactam (EC) manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, M.; Yoshida, Y.

    1979-09-01

    Sulfur dioxide in boiler exhaust gas from high-sulfur, heavy oil combustion is used at the Sakai caprolactam plant of Ube Industries Ltd. At this plant, 20,000 tons/yr out of a total 90,000 tons/yr of EC is prepared by the reaction of cyclohexanone with hydroxylamine, which is in turn prepared by the Raschig synthesis, which involves reduction by sulfur dioxide of aqueous ammonium nitrite prepared by absorption of N/sub 2/O/sub 3/ into aqueous ammonium bisulfite. For SO/sub 2/ absorption, the flue gas is cooled to about 60/sup 0/C by isothermal cooling with the absorption solution. The SO/sub 2/ absorption reaction occurs in liquid phase at pH 5-5.8 in the absence of free ammonia, since otherwise, an aerosol would form. After further absorption of SO/sub 2/ from flue gas in a second absorber of the same type (which uses a different concentration of absorption liquid), the SO/sub 2/ in the flue gas is diminished to 40-60 ppm from its original 1300 ppm concentration. The chemistry and performance of the SO/sub 2/ absorption procedure, including the composition of the crude ammonium bisulfite solution during the absorption reactions, and of the Raschig process are discussed.

  18. In Silico Identification for α-Amino-ε-Caprolactam Racemases by Using Information on the Structure and Function Relationship.

    Science.gov (United States)

    Payoungkiattikun, Wisarut; Okazaki, Seiji; Nakano, Shogo; Ina, Atsutoshi; H-Kittikun, Aran; Asano, Yasuhisa

    2015-07-01

    In silico identification for enzymes having desired functions is attractive because there is a possibility that numerous desirable enzymes have been deposited in databases. In this study, α-amino-ε-caprolactam (ACL) racemases were searched from the NCBI protein database. Four hundred thirteen fold-type I pyridoxal 5'-phosphate-dependent enzymes which are considered to contain sequences of ACL racemase were firstly obtained by submitting the sequence of ACL racemase from Achromobacter obae to the database. By identifying Lys241 as a key amino acid residue, 13 candidates for ACL racemase were selected. Then, putative ACL racemase genes were synthesized as codon-optimized sequences for expression in Escherichia coli. They were subcloned and expressed in E. coli BL21 and underwent His-tag purification. ACL and amino acid amide racemizing activities were detected among ten of the candidates. The locus tags Oant_4493, Smed_5339, and CSE45_2055 derived from Ochrobactrum anthropi ATCC49188, Sinorhizobium medicae WSM 419, and Citreicella sp. SE45, respectively, showed higher racemization activity against D- and L-ACLs rather than that of ACL racemase from A. obae. Our results demonstrate that the newly discovered ACL racemases were unique from ACL racemase from A. obae and might be useful for applications in dynamic kinetic resolution for D- or L-amino acid production.

  19. Spectroscopic study on the active site of a SiO2 supported niobia catalyst used for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam

    NARCIS (Netherlands)

    Maronna, M M; Kruissink, E C; Parton, R F; Soulimani, F; Weckhuysen, B M; Hoelderich, W F

    2016-01-01

    NbOx/SiO2 with a very high catalytic activity for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam, was investigated by different spectroscopic methods in order to obtain new insights in the formation and nature of the active sites. FT-IR spectroscopy in combination with

  20. NbOx/SiO2 in the gas-phase Beckmann rearrangement of cyclohexanone oxime to epsilon-caprolactam: Influence of calcination temperature, niobia loading and silylation post-treatment

    NARCIS (Netherlands)

    Maronna, M. M.; Kruissink, E. C.; Parton, R. F.; Tinge, J. T.; Soulimani, F.; Weckhuysen, B. M.; Hoelderich, W. F.

    2016-01-01

    NbOx/SiO2 catalyst materials prepared by the incipient wetness impregnation method were studied in the industrially relevant gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam. The catalytic experiments were carried out in a fixed bed reactor system at atmospheric pressure. Res

  1. Synthesis and characterization of alternating poly(amide urea)s and poly(amide urethane urethane)s from ε-caprolactam, diamines, and diphenyl carbonate or ethylene carbonate

    NARCIS (Netherlands)

    Ubaghs, Luc; Sharma, Bhaskar; Keul, Helmut; Höcker, Hartwig; Loontjens, Ton; Benthem, Rolf van

    2003-01-01

    Alternating poly(amide urea)s from ε-caprolactam, diamines H2N-(CH2)x-NH2 (x = 2 - 4), and diphenyl carbonate were prepared in two steps. The microstructure of the poly(amide urea)s, as determined by means of 1H NMR spectroscopy, reveals a strictly alternating sequence of the building blocks. The mo

  2. Growth of ɛ-caprolactam crystals from the melt: The influence of cyclohexanone on the {1 1 1¯} and {1 1 0} forms

    Science.gov (United States)

    van den Berg, E. P. G.; Bögels, G.; Arkenbout, G. J.

    1998-01-01

    The (1 1 1¯) and (1 1 0) facets of ɛ-caprolactam growing from the melt appear to grow with different mechanisms. This is caused by the different molecular structure of the (1 1 1¯) and the (1 1 0) facets. Moreover, the cyclohexanone impurity concentration in front of the interface changes the growth mechanism leading to different distribution coefficients for each facet. Usually, in industry overall distribution coefficients are used and the crystal form is only of interest because of the filterability of the crystals. Here it is shown that a second factor, the growth mechanism of each facet has to be taken into account when considering the optimal conditions for growing pure crystals.

  3. Control Methods of the Content of Volatile Base Impurities in Caprolactam%己内酰胺中挥发性碱杂质的控制

    Institute of Scientific and Technical Information of China (English)

    胡合新; 孙斌; 王恩泉

    2012-01-01

    针对己内酰胺成品中C3~C7直链酰胺、苯胺和己二酰亚胺等挥发性碱杂质含量偏高,影响产品质量的问题、研究了杂质控制方法.考察了真空蒸馏、树脂吸附、酸性/碱性水解等方法降低挥发性碱杂质含量的效果,并跟踪分析了工业装置中环己酮杂质对己内酰胺产品质量的影响.结果表明,真空蒸馏仅能脱除约20%正戊酰胺;Amberlyst强酸性树脂容易吸附脱除碱性较强的NH3,而难以吸附脱除碱性弱的正戊酰胺、正己酰胺;NaOH质量分数由0增至500μg/g时,加速了挥发性碱杂质的水解速率,但也促进己内酰胺开环水解、低聚等副反应;H2SO;溶液中添加NaNO2进行重氮化反应,明显加快了正戊酰胺、正己酰胺的水解速率,但大量己内酰胺同时存在时,H2SO4易与己内酰胺发生络合反应,导致杂质基本不进行水解反应.通过严格限制环己酮中己醛和2-庚酮杂质质量分数至20~30 μg/g,挥发性碱杂质含量明显下降,己内酰胺优级品率可达到100%.%To solve off-specification problem of caprolactam, caused by the volatile base impurities, such as C3-C7 amides, C6 imides and aniline, some methods to control the content of volatile base impurities were investigated, including vacuum distillation, resin adsorption, hydrolysis. Results showed that only 20% (mass fraction) of pentylamide was removed by vacuum distillation. Removal efficiency of ammonia on strongly acidic cation exchange resin Amberlyst was higher than that of pentylamide and hexoamide, which might be attributed to the stronger alkalinity of ammonia. As the NaOH mass fraction increased from 0 to 500 μg/g, hydrolysis rates of pentylamide and hexoamide were promoted, but the ring-opening polymerization of caprolactam increased simultaneously. As adding NaNO2 in the H2SO4 solution, conversions of pentylamide and hexoamide increased significantly. However, if caprolactam existed in the H2SO4 solution system

  4. STUDY ON THE BIODEGRADABILITY OF CAPROLACTAM PRODUCTION WASTEWATER%己内酰胺生产污水可生化性研究

    Institute of Scientific and Technical Information of China (English)

    刘久清; 王春志; 刘婉蓉; 蒋彬; 杨秋菊; 吴明

    2009-01-01

    针对已内酰胺生产中,石油科学研究院开发的单釜连续淤浆床合成环己酮肟工业装置产生的工业废水进行了可生化性研究.结果表明,在pH为3,温度100℃以下,停留时间30min后,废水中的过氧化物含量可减少90%以上,废水的COD下降50%以上,同时废水的B/C比由0.01提高到0.4以上,达到了废水可生化的要求.%For the production of caprolactam, Industrial wastewater produced by a single continuous slurry-bed pot synthesis of cyclohexanone oxime plant developed by oil research institute can be carried out biodegradability research. It''s showed that: when the pH was 3, the temperature was below 100℃, the residence time was more than 30 minutes, the peroxide content of the wastewater could be reduced more than 90%, COD dropped more than 50%, and at the same time B/C increased from 0.01 to 0.4 and more, then the wastewater could meet the wastewater biochemical requirements.

  5. Effect of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer on bioadhesion and release rate property of eplerenone pellets.

    Science.gov (United States)

    Kendre, Prakash Namdeo; Chaudhari, Pravin Digambar

    2017-05-01

    The present study involved the design and development of oral bioadhesive pellets of eplerenone. A solid dispersion of eplerenone was developed with a hydrophilic carrier, polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus(®)). Bioadhesive pellets were prepared from this solid dispersion using a combination of HPMC K4M and Carbopol 934P. Both the solid dispersion and the pellets were evaluated for various physicochemical properties such as solubility, entrapment efficiency, drug content, surface morphology, mucoadhesion and swelling behavior. Analysis carried out using FT-IR, DSC and XRD found no interaction between the eplerenone and excipients. The solid dispersion had irregular-shaped smooth-surfaced particles of diameter 265 ± 105.5 μm. In TEM analysis, eplerenone particles of size 79-120 nm were found. The solubility and dissolution of eplerenone in the Soluplus(®)-based solid dispersion were 5.26 and 2.50 times greater, respectively. Investigation of the swelling behavior of the pellets showed that the thickness of the gel layer increased continuously over the duration of the study. Moreover, a correlation was observed between the thickness and strength of the gel layer and the percentage release. The mechanism of drug release was found to be non-Fickian (anomalous), with the release kinetics approaching first-order kinetics. The bioavailability of the eplerenone bioadhesive pellet formulation was studied using Wistar rats and was found to be improved. An in vivo mucoadhesion study showed that the pellets are retained for 24 h in rabbits. It was concluded that Soluplus(®) had a positive effect on the solubility and dissolution of pellets without affecting the bioadhesion.

  6. 磺酸树脂Amberlyst70催化环己酮肟液相重排制己内酰胺%LIQUID PHASE REARRANGEMENT OF CYCLOHEXANONE OXIME TO ε-CAPROLACTAM CATALYZED BY AMBERLYST 70 SULFOACID RESIN

    Institute of Scientific and Technical Information of China (English)

    刘贤响; 毛丽秋; 徐琼; 钟文周; 尹笃林

    2011-01-01

    Preparing e-caprolactam by liquid-phase Beckmann rearrangement of cyclohexanone oxime is attractive in current study. The catalytic performance of Amberlyst 70 sulfoacid resin catalyst in the rearrangement was researched. Various reaction parameters such as reaction time, reaction temperature, amounts of catalyst and other factors influencing the rearrangement were discussed. The optimum conditions were: temperature 130 ℃ , the mass ratio of reactants and catalyst 1. 13:1 and reaction time 6 h. Under these conditions, the conversion of cyclohexanone oxime and the selectivity of e-caprolactam were above 99. 4% and 90. 2% , respectively. Results of further experiments showed that Amberlyst 70 had high catalytic activity to liquid-phase Beckmann rearrangement of cyclohexanone oxime and the deactivated catalyst could be was easily regenerated.%实验以大孔氢型耐高温磺酸树脂Amberlyst 70为催化剂,环己酮肟液相重排制已内酰胺.考察了反应温度、反应时间、催化剂用量等因素对重排反应的影响.实验结果表明:常压下、温度为130℃、m(环己酮肟):m(催化剂)=1.13:1,反应6h,环己酮肟转化率可达99.4%,己内酰胺的选择性可达90.2%.该催化剂催化效率高,经再生可恢复较好的活性,便于重复利用.

  7. Research on the vapor phase Beckmann rearrangement process of cyclohexanone oxime to caprolactam%环己酮肟气相重排制备己内酰胺工艺

    Institute of Scientific and Technical Information of China (English)

    史雪芳; 丁克鸿

    2013-01-01

    报道了一种具有MFI结构的高硅亚微米级分子筛MS1,该分子筛制备工艺简便、成本低、环境友好.研究了MS1分子筛催化环己酮肟气相Beckmann重排制备己内酰胺的催化效果,考察了汽化温度、反应温度、环己酮肟浓度及质量空速(WHSV)等反应条件对环己酮肟气相Beckmann重排反应的影响;在优化的反应条件下环己酮肟转化率≥99.5%,己内酰胺选择性达95%,且催化剂稳定性较好;结果表明,MS1分子筛催化剂具有良好的工业化应用前景.%This paper reports a high silicon submicron molecular sieve with MFI structure. The molecular sieve preparation process is simple, low-cost and environment friendly. The vapor phase Beckmann rearrangement catalytic effect of MS1 zeolite catalytic cyclohexanone oxime(CHO) to caprolactam has been studied. The influences of vaporization temperature, reaction temperature, CHO concentration and WHSV of CHO on the vapor phase Beckmann rearrangement of CHO were investigated. 99.5% of the cyclohexanone oxime conversion rate and 95% of the caprolactam were achieved with better catalyst stability. The results show that MS1 zeolite catalyst has a good potential in industrial application.

  8. S-1催化环己酮肟气相Beckmann重排反应动力学%Kinetics of S-1 catalyzed vapor phase Beckmann rearrangement of cyclohexanone oxime to caprolactam

    Institute of Scientific and Technical Information of China (English)

    金星; 孟凡会; 王书海; 王亚权

    2013-01-01

    Caprolactam, the intermediate for the production of Nylon-6, is mainly produced through sulfuric acid catalyzed liquid phase Beckmann rearrangement of cyclohexanone oxime. This process has several disadvantages, such as the corrosion of reactors and by-production of a large amount of ammonium sulfate. These shortcomings can be prevented by vapor phase Beckmann rearrangement. In this work, the kinetics of vapor phase Beckmann rearrangement of cyclohexanone oxime to caprolactam was studied by both experiments and modeling. The results showed that the changes of catalyst activity with online reaction time could be correlated with the catalyst deactivation model developed by Wojciechowski, from which the kinetic equation and the corresponding parameters of the reaction were obtained. The results could be used to calculate deactivation rates at any online reaction time or catalyst life at the permissible lower conversion.%目前尼龙6生产中主要采用发烟硫酸催化环己酮肟液相Beckmann重排制己内酰胺,副产大量硫酸铵,而且存在设备腐蚀等问题.采用气相重排法可以克服上述缺点.本工作在以前得到的优化反应条件下,根据实验并采用催化剂失活的Wojciechowski模型获得了S-1催化环己酮肟气相Beckmann重排制己内酰胺反应动力学方程及参数.该模型将催化剂的活性与在线反应时间相关联,进而可以计算任何在线反应时间时催化剂的失活速率,或者根据要求的转化率最低允许值计算催化剂能在线反应的时间.

  9. Spectroscopic study on the active site of a SiO2 supported niobia catalyst used for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam.

    Science.gov (United States)

    Maronna, M M; Kruissink, E C; Parton, R F; Soulimani, F; Weckhuysen, B M; Hoelderich, W F

    2016-08-10

    NbOx/SiO2 with a very high catalytic activity for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam, was investigated by different spectroscopic methods in order to obtain new insights in the formation and nature of the active sites. FT-IR spectroscopy in combination with pyridine adsorption measurements revealed that the catalyst material contains Lewis-acidic sites, most probably related to the Nb[double bond, length as m-dash]O groups of isolated tetrahedral NbO4 surface species, whereas no Brønsted-acidic sites were observed. Results from in situ Raman and complementary FT-IR measurements strongly suggest that Brønsted-acidic Nb-OH sites can be generated from Nb[double bond, length as m-dash]O groups by reaction with ethanol. This is in agreement with the observation that ethanol is essential for obtaining a very good catalyst performance. However, the Brønsted-acidic sites can be detected in significant amounts in particular in the presence of a Lewis-base, e.g. pyridine, most probably because the formation and/or the stability of these Brønsted-acidic sites are enhanced by a basic molecule. Assuming that cyclohexanone oxime, being a base, can play a similar role as pyridine, we propose on the basis of the spectroscopic findings obtained in this work and our kinetic results published recently, a reaction scheme for the formation of the active site at the Nb[double bond, length as m-dash]O group as well as for the recovery of the Nb[double bond, length as m-dash]O site during the final stage of the gas-phase Beckmann rearrangement.

  10. Study on the Preparation and Properties of Caprolactam and Octamethyl Cyclotetrasiloxane Copolymer%己内酰胺与八甲基环四硅氧烷共聚物的合成及性能研究

    Institute of Scientific and Technical Information of China (English)

    任庆佩; 孙丹丹; 朱晓清; 潘庆华; 马清芳; 郝超伟

    2015-01-01

    通过己内酰胺与八甲基环四硅氧烷的阴离子共聚合反应制取D4/PA6共聚物,并对其热力学和力学性能进行了系统分析.TGA分析结果表明,八甲基环四硅氧烷的加入不影响PA6的热稳定性.DSC分析结果表明,随着D4含量的增加,PA6的结晶温度和熔融温度均有先增加后减小的趋势.力学测试结果表明,含4% D4时断裂伸长率可达12.671%,其韧性有所提高.%The D4/PA6 copolymer was prepared by the copolymerization with caprolactam and octamethyl cyclotetrasiloxane ,the thermodynamic and mechanical properties of which were also analyzed .TGA analysis showed that D4 could not clearly affect the thermal stability of PA 6 .DSC analysis showed that crystallization and melting temperatures of PA6 first increased and then slightly decreased with increasing content of D 4 .And the mechanical test analysis exhibited that the elongation at break of the copolymer could approach 12 .671% with the 4% content of D4 ,which implied that the toughness of the copolymer was improved .

  11. Migração de β-caprolactama de embalagens contendo poliamida 6 para simulante ácido acético 3% e validação do método analítico β-Caprolactam migration from polyamide 6 packaging into 3% acetic acid food simulant and validation of the analytical method

    Directory of Open Access Journals (Sweden)

    Juliana Silva Félix

    2007-08-01

    Full Text Available Este trabalho teve como objetivo desenvolver e validar método analítico para determinar ε-caprolactama no simulante de alimentos solução de ácido acético 3% e estudar sua migração de embalagens contendo poliamida 6 para o simulante em contato. Foi empregada a cromatografia gasosa usando ε-caprolactama como padrão analítico e 2-azociclononanona como padrão interno. A linearidade esteve entre 1,60 e 640,00 µg de ε-caprolactama.mL-1 de simulante, com coeficiente de correlação 0,9999. Os limites de detecção e de quantificação do método foram 0,24 e 1,60 ng, respectivamente. A precisão do método revelou valores de coeficiente de variação menores que 4,3% e a avaliação da exatidão mostrou recuperação de 100 a 106%. O método demonstrou ser eficaz para quantificar ε-caprolactama no simulante, apresentando ampla linearidade, boa precisão e exatidão. No ensaio de migração, embalagens contendo poliamida 6 foram colocadas em tubos de vidro com 10 mL do simulante, que foram hermeticamente fechados e acondicionados a 40 ± 1 °C durante 10 dias. O ensaio de migração foi realizado por imersão total. A quantidade de ε-caprolactama migrada variou de 7,8 a 10,5 e de 6,9 a 7,6 mg.kg-1 de simulante para as embalagens destinadas aos produtos cárneos e queijos, respectivamente. Todas as embalagens atenderam às exigências da Legislação Brasileira para migração de ε-caprolactama.The aim of this work was to develop and validate an analytical method to determine ε-caprolactam in 3% acetic acid solution and to study its migration from polyamide 6 into food simulant. Gas chromatography was used with ε-caprolactam as an analytical standard and 2-azacyclononanone as an internal standard. The linearity was obtained by the concentration range of 1.60 to 640.00 µg.mL-1, with a correlation coefficient of 0.9999. Detection and quantification limits of the method were 0.24 ng and 1.60 ng, respectively. Relative standard

  12. Melamine-Formadehyde Resin Modified with Diglycol-Caprolactam and Its Application in Liquid Wear-Resistant Technology%三聚氰胺甲醛树脂的聚合机理及其在液体耐磨技术中的应用

    Institute of Scientific and Technical Information of China (English)

    连海兰; 赵丽艳; 洪枢; 孙香; 詹先旭

    2014-01-01

    通过13 C-NMR分析二乙二醇和己内酰胺改性的三聚氰胺甲醛树脂( CMF )的结构及聚合机理,结合耐磨颗粒Al2 O3的表面改性研究,探讨将其应用于制备液体耐磨纸的可行性。结果表明:二乙二醇和己内酰胺可以与羟甲基三聚氰胺上的活泼氢原子反应,生成由次甲基键和醚键连接的聚合物。己内酰胺在反应过程中存在开环反应,水解成氨基羧酸后与羟甲基三聚氰胺发生酯化反应,由其改性的CMF树脂的贮存期达15 d以上;使用1.5%的复合偶联剂改性Al2O3(YB-501-Al2O3),按CMF树脂、YB-501-Al2O3、羧甲基纤维素钠(CMC)的质量分数分别为84.5%、15.0%、0.5%,制造Al2 O3添加量为45 g/m2的耐磨装饰纸,在热压温度200℃、压力2.5 MPa和时间60 s的条件下制成的强化木地板耐磨转数可达4700 r,满足国家标准GB/T 18102-2007中家用Ⅱ级的使用要求。%We examined the mechanism of polymerization and structure of the CMF resins by 13C-NMR spectroscopy .Combining with modification of Al2O3 surface, we obtained the final wear-resistant resin for decorative paper .The diethylene glycol and caprolactam could react with the active hydrogen of methylol melamine , and generate the polymer linkage of -CH2-and CH2-O-CH2.The esterification reaction occurred between methylol melamine and amino acid after the caprolactam was ring-opening and hydrolyzed into amino acid .The storage period of this kind of CMF resin were more than 15 days.By FTIR analysis, Al2O3 modified by coupling agent (YB-501) of 1.5%was the optimum and the ability of wear resistance was also good.The optimal dosages of liquid resin were 84.5%of CMF resin with the amount of 15%modified Al2O3, the dispersant concentration ( CMC) was 0.5%, and the curing agent PTSA ( based on the mass of CMF resin ) was 0.5%.Un-der the hot-press temperature of 200℃, hot-pressure of 2.5 MPa and 60 s, the covered panel had a good

  13. 己内酰胺联产工艺中影响成品290nm处吸光度杂质的定性定量分析%Qualitative and Quantitative Analysis of Impurities in the Products of Combined Caprolactam Process, Affecting Absorbency at 290 nm

    Institute of Scientific and Technical Information of China (English)

    尹学军; 李竞; 袁霞; 吴剑; 罗和安

    2012-01-01

    An impurity, which affected the absorbency at 290 nm in the ultraviolet spectro-photometry, in the caprolactam products synthesized from cyclohexanecarboxylic acid and cyclohexanone oxime was analyzed by means of GC-MS. The results showed that it was octahydrophenazine. The linear correlativity was found between the concentration of octahydrophenazine and the absorbency at 290 nm. It was indicated that the octahydrophenazine derived from Neber rearrangement products which existed in the Beckmann rearrangement of cyclohexanone oxime when the system lacked sulfuric acid. The octahydrophenazine was analyzed quantificationally by means of HPLC and the optimal conditions were obtained as follows: C18 chromatographic column(4.6 mm × 250 mm × 5 nm), acetonitrile and water(volume ratio 30 : 70) as mobile phase with a flow rate of 1.0 mL/min and detection wavelength of the ultraviolet spectrophotometry 290 nm. This method was proved to have the advantages of precise, rapidity and simplicity.%利用气相色谱-质谱联用技术对环己烷羧酸-环己酮肟联产己内酰胺工艺中影响成品在290 nm处的吸光度的杂质进行了定性分析.分析结果表明,联产工艺生产的己内酰胺中含有八氢吩嗪.利用紫外分光光度法证实了八氢吩嗪的含量与290nm处的吸光度存在近似线性的相关性,因而推断八氢吩嗪为影响产品在290 nm处吸光度的主要杂质.反应机理的研究结果表明,八氢吩嗪是由环己酮肟Beckmann重排过程局部硫酸量不足,环己酮肟硫酸酯发生Neber重排形成的连氮化合物衍生而成.建立了八氢吩嗪的高效液相色谱分析方法,较优的分析条件为:C18色谱柱(4.6 mm×250 mm× 5μm),流动相为体积比为30∶70的乙腈-水溶液,流量1.0 mL/min,紫外检测器检测波长290 nm.该方法具有准确、快速和简单的优点.

  14. H-ZSM-5催化环己酮肟制ε-己内酰胺反应机理的O NIO M研究%Reaction Mechanism of Cyclohexanone Oxime to ε-Caprolactam Catalyzed over H-ZSM-5:An ONIOM Study

    Institute of Scientific and Technical Information of China (English)

    王寒露; 周建敏; 周如金

    2014-01-01

    The Backman rearrangement reaction mechanism of cyclohexanone oxime to ε-caprolactam over the H-ZSM-5 zeolite was investigated by the ONIOM and DFT methods.All geometry structures optimization were em-ployed ONIOM (B3LYP/6-31+G(d):PM3)method.Based on the optimal configuration,a high single point cal-culation of complete 46T cluster model were carried out by a variety of density functionals,such as B3LYP/6-31+G(d),PBE/6-31+G(d),M062X/6-31+G(d)andωB97XD/6-31+G(d).Additional dispersion corrections were calculated by dftd3 program to describe the weak interaction in zeolites for B3LYP,PBE and M062X functionals. The calculation results showed that the precision of the DFT functionals for dispersion correction was greatly im-proved,which were comparable with the MP2 method.The rate determining step was the first step 1 ,2-H shift and rearrangement step,and internal reaction energy barrier was 44.5 kcal/mol.The reaction rate constants indicated that the Beckman rearrangement reaction was very slowly on the H-ZSM-5 at 293-393 K.When the temperature reached 423 K,the forward and reverse reaction rate were about the same,and the reaction occurred.When reached 623 K,the reaction rate constant was 130 1/s.%采用ONIOM和DFT方法研究了H-ZSM-5分子筛催化环己酮肟制ε-己内酰胺的贝克曼重排反应机理.所有的构型优化使用ONIOM(B3LYP/6-31+G(d):PM3)方法进行,并在此基础上对得到的最优构型应用多种密度泛度方法,如B3LYP/6-31+G(d),PBE/6-31+G(d),M062X/6-31+G(d)和ωB97XD/6-31+G(d)进行完整46T簇模型的单点能计算.B3LYP,PBE和M062X泛函使用dftd3程序计算了额外色散校正,以考虑分子筛内部的弱相互作用.计算结果显示,经色散校正的DFT方法的计算精度被大大提高,达到一个与MP2方法相媲美的精度.反应的决速步是由第一步1,2-H转移和重排步共同决定,内部反应能垒为44.5 kcal/mol.

  15. Simultaneous determination of 1-sulfo-cyclohexane carboxylic acid and sulfate anion in the by-products of caprolactam by high performance liquid chromatography-indirect photometric analysis%高效液相色谱-间接光度法同时检测己内酰胺副产物中1-磷酸环己烷羧酸及硫酸根离子

    Institute of Scientific and Technical Information of China (English)

    颜志祥; 段正康; 李立南; 李海涛; 陈秋云; 彭叶

    2013-01-01

    提出了一种能够同时检测具有紫外吸收(UV)的有机物和无紫外吸收的无机物含量的强阴离子交换色谱法(IEC).以检测己内酰胺副产物中的1-磺酸基环己烷羧酸(SCCA)粗盐为具体实例开展研究.强阴离子色谱柱以及UV检测器被用于同时分析SCCA和硫酸根离子.本实验基于高效液相色谱-间接光度检测法(HPLC-IPD)原理来测定SCCA和硫酸根离子,选用具有强紫外吸收能力的邻苯二甲酸作为本底试剂加入到流动相中产生信号.硫酸根离子和SCCA分别在0.10 ~ 10.0 g/L和0.50~40.0g/L范围内呈良好的线性关系,相关系数分别为0.999 14和0.999 97;加标回收率分别为98.50% ~ 101.00%和93.33% ~ 97.40%,定量限均为0.10 g/L,符合色谱检测要求.该方法具有良好的分离选择性,可用于SCCA和硫酸根离子的同时检测.%An improved anion-exchange chromatographic method was developed for simultaneous quantification of 1-sulfo-cyclohexane carboxylic acid (SCCA) and sulfate anion in the by-products of caprolactam. An strong anion chromatographic column and an ultraviolet (UV) detector were chosen for the assay of SCCA and sulfate anion. Non-chromophore-containing sulfate anion is not directly adaptable to the commonly used ultraviolet detection of high performance liquid chromatography (HPLC). This paper reports the development and validation of an HPLC assay for SCCA and sulfate anion based on indirect ultraviolet detection. An ultraviolet-absorbing reagent (the probe), phthalic acid (PA), was added to the mobile phase to induce a signal for the compound. The proposed method was qualified based on the performance criteria of repeatability, intermediate precision and linearity. The limits of detection were 1. 0 g/L for both the analytes. The linear ranges varied from 0. 50 to 40. 0 g/L for SCCA and from 0. 10 to 10.0 g/L for sulfate anion, with the correlation coefficients of 0.999 97 and 0. 999 14, and the recoveries of

  16. Hydrogen bonding induced polymorphism in the scandium(III) complex with ε-caprolactam

    Energy Technology Data Exchange (ETDEWEB)

    Virovets, Alexander V.; Peresypkina, Eugenia V. [Institute of Inorganic Chemistry SB RAS, Novosibirsk (Russian Federation); Novosibirsk State Univ. (Russian Federation); Cherkasova, Elizaveta V.; Cherkasova, Tatjana G. [Kuzbass State Technical Univ., Kemerovo (Russian Federation)

    2015-11-01

    Two polymorphs of [Sc(cpl){sub 6}][Cr(NCS){sub 6}] (cpl=ε- C{sub 6}H{sub 11}NO), trigonal and monoclinic, form purple elongated narrow plates and brownish-purple prisms and are formed concomitantly irrespectively of the crystallization conditions. In the trigonal polymorph both cation and anion possess C{sub 3i} site symmetry while in the monoclinic form cation and anion lie on inversion centre and 2-fold axis respectively. The nature of the polymorphism traces back to a redistribution of inter- and intramolecular hydrogen bonds that causes different conformation of the complex cations, different hydrogen bonding and different molecular packings. The [Sc(cpl){sub 6}]{sup 3+} cations in the structure of the trigonal polymorph form intermolecular N(H)..S, and in the monoclinic form both N(H)..S inter- and N(H)..O intramolecular hydrogen bonds with NCS groups of [Cr(NCS){sub 6}]{sup 3-} and cpl ligands. This aggregation leads to chains, where the cations and the anions alternate, in the trigonal modification and to layers, in which each ion is surrounded by four counterions, in the monoclinic form. Both polymorphs possess thermochromic properties, and a reversible color change from light purple to dark green takes place at 470-475 K.

  17. Dynamic melt flow of nanocomposites based on poly-epsilon-caprolactam

    DEFF Research Database (Denmark)

    Utracki, Leszek; Lyngaae-Jørgensen, Jørgen

    2002-01-01

    The dynamic flow behavior of polyamide-6 (PA-6) and a nanocomposite (PNC) based on it was studied. The latter resin contained 2 wt% of organoclay. The two materials were blended in proportions of 0, 25, 50, 75, and 100 wt% PNC. The dynamic shear rheological properties of well-dried specimens were...

  18. Progress in Caprolactam Production Technologies Routes%己内酰胺生产技术路线进展

    Institute of Scientific and Technical Information of China (English)

    吴惠; 丁克鸿

    2014-01-01

    文章综述了生产己内酰胺(CPL)的几种典型工艺,说明了环己酮肟Beckmann重排是目前生产CPL中最重要的反应之一.着重从环保、经济性等方面对环己酮肟液相重排与气相重排制备己内酰胺进行比较,结果表明,使用MFI型硅分子筛催化环己酮肟Bcckmann气相重排制备己内酰胺的绿色新工艺,具有良好的工业化应用前景.

  19. 环己酮肟贝克曼重排反应动力学%Kinetics of Beckmann Rearrangement Reaction of Cyclohexanone Oxime for Caprolactam

    Institute of Scientific and Technical Information of China (English)

    李海生; 吴剑; 王良芥; 罗和安

    2002-01-01

    通过对环己酮肟贝克曼重排反应机理的分析和简化,提出了一个反应动力学模型同时考虑了SO3和H+在反应过程中的作用.根据文献数据对模型进行了参数估计,计算结果不仅与高SO3浓度下的文献数据吻合良好,也能较好地解释低SO3浓度下的工业反应过程现象.该模型为工业重排反应过程的设计和优化提供了一定的依据.

  20. 环己酮肟液相Beckmann重排制己内酰胺研究进展%Liquid-phase Beckmann rearrangement of cyclohexanone oxime into caprolactam

    Institute of Scientific and Technical Information of China (English)

    肖朝辉; 李惠友; 魏运方

    2005-01-01

    综述了不使用浓硫酸为催化剂的环己酮肟液相Beckmann重排生产己内酰胺的研究进展.重点介绍了分子筛等固体酸催化剂、烷基化试剂和DMF组成的催化体系、离子液体催化体系、超f临界水及超临界CO2条件下的液相重排新工艺,指出采用新型催化剂的绿色生产工艺,特别是离子液体催化体系具有良好的开发应用前景.

  1. Research Progress of Beckmann Rearrangement of Cyclohexanone Oxime to Caprolactam%环己酮肟Beckmann重排制己内酰胺的研究进展

    Institute of Scientific and Technical Information of China (English)

    游军杰; 徐军; 郭士岭; 陈宜良

    2003-01-01

    环己酮肟Beckmann重排制己内酰胺是重要的工业过程.本文较详细地介绍了不使用浓硫酸催化的反应,主要有气固相反应、固液相反应、离子液体系及超临界水条件下的反应.研究表明:气固相反应中,副产物较多,催化剂易失活,使用寿命短;固液相反应条件温和,且副产物少;离子液体系和超临界水条件下的Beckmann反应中,可避免使用有机溶剂,且反应副产物少.

  2. Increasing Global Market Share of the Caprolactam Business%提高己内酰胺的全球市场份额

    Institute of Scientific and Technical Information of China (English)

    本刊欧洲特约撰稿人

    2001-01-01

    DSM是一家主营纤维中间体的跨国公司,总部设在荷兰.DSM公司实力雄厚,尤其在己内酰胺业居领先地位.文章介绍了DSM公司未来5年中在己内酰胺领域的致力目标及市场前景.

  3. 己内酰胺与十二内酰胺共聚尼龙的合成%The Synthesis of Nylon Copolymer f rom Caprolactam and Laurolactam

    Institute of Scientific and Technical Information of China (English)

    孙丹丹; 李江; 任庆佩; 潘庆华; 马清芳; 郝超伟

    2014-01-01

    The nylon 6-12 copolymer is prepared by anionic ring-opening polymerization .The results of TGA analysis show that the addition of laurolactam strengthens the thermal stability of nylon .The results of DSC analysis indicate that the addition of laurolactam increase the irregularity of nylon chain , decrease both the density of hydrogen bond and the crystallinity .The infrared spectra of NH group exhibit red shift phenomenon as well .%通过阴离子开环聚合的方法制备了共聚尼龙6-12.TGA 分析结果显示随着十二内酰胺的加入尼龙的热稳定性增强;DSC分析结果表明十二内酰胺的加入使得尼龙链段的混乱度增加,氢键密度减少,结晶度下降;同时共聚物红外谱图中-NH的特征峰出现红移.

  4. Influence of Laurolactam Content on the Clay Intercalation of Polyamide 6,12/Clay Nanocomposites Synthesized by Open Ring Anionic Polymerization

    OpenAIRE

    E. N. Cabrera Álvarez; L. F. Ramos de Valle; Rodríguez González, F. J.; Soriano-Corral, F.; Díaz De León, R. E.

    2012-01-01

    In situ anionic homo- and copolymerization of caprolactam (CL) and laurolactam (LL) with sodium montmorillonite clay (NaMMT) was carried out using two different initiators, sodium caprolactamate (CLNa) and caprolactam magnesium bromide (CLMgBr). Degree of conversion and final molecular weight were used to assess the advancement and efficiency of the polymerization reaction and X-ray diffraction and electron microscopy were used to evaluate the sodium montmorillonite clay intercalation/exfolia...

  5. Catalytic Beckmann Rearrangement of Cyclohexanone Oxime intoε-Caprolactam in Ionic Liquids%离子液体系中催化环己酮肟重排制己内酰胺

    Institute of Scientific and Technical Information of China (English)

    彭家建; 邓友全

    2001-01-01

    发现由室温离子液体1-丁基-3-甲基咪唑三氟乙酸盐、正丁基吡啶氟硼酸盐等和含磷化合物组成的催化体系,可以高效地实现对环己酮肟重排制己内酰胺的反应,具有不再用有机溶剂、反应副产物少等特点;并考察了含磷化合物用量和反应温度对反应的转化率和选择性的影响。%Beckmannrearrangement of cyclohexanone oxime has been studied in catalytic med ium composed of ionic liquids and phosph orous-containing compounds such as phosp horous pentachloride without the presenc e of any other organic solvent.The trans formation was found to proceed very effe ctively under mild conditions.The influe nce of the amount of phosphorous-contain ing compounds and the reaction temperatu re on the reaction was also investigated .

  6. Research progress in Green catalytic Beckmann rearrangement of cyclohexanone oxime into caprolactam%环己酮肟贝克曼重排制己内酰胺绿色催化研究进展

    Institute of Scientific and Technical Information of China (English)

    周云; 卢建国; 朱明乔

    2015-01-01

    己内酰胺是一种重要的有机化工原料,其传统的环己酮肟贝克曼重排制己内酰胺是以发烟硫酸为催化剂的生产工艺,存在污染环境、设备腐蚀以及成本高等缺点.综述了环己酮肟贝克曼重排反应制己内酰胺的绿色催化研究进展;介绍了氧化物催化剂、钛硅分子筛催化剂,及离子液体在催化中的应用;氧化物催化剂具有较好的催化活性,但存在寿命短、再生性差的缺点;TS-1型分子筛催化剂成本高,重现性差,工业化生产有待进一步研究;S-1型分子筛催化剂催化性能好,但反应条件较苛刻,使用寿命短;离子液体作为催化剂选择性不高.指出气相重排工艺绿色催化的高硅分子筛,特别是S-1型分子筛,具有较理想的催化效果,进一步提高全硅分子筛催化剂的选择性、延长使用寿命是今后研究的重点.

  7. 环己酮肟两步转位工艺在己内酰胺装置中的应用%Application of Two-step Cyclohexanone Oxime Transfer Process in The Caprolactam Plant

    Institute of Scientific and Technical Information of China (English)

    杨春和

    2004-01-01

    分析了环己酮肟转位反应,将我国自行开发的环己酮肟两步转位工艺应用到己内酰胺生产中,与原一步转位工艺相比较,结果表明:转位工艺条件明显优化,得到了1.2:1.0的发烟硫酸与环己酮肟摩尔比,降低了发烟硫酸和氨的消耗定额,提高了己内酰胺产品质量.

  8. STUDY ON REFINING OF CAPROLACTAM FROM VAPOR-PHASE BECKMANN REARRANGEMENT REACTION OF CYCLOHEXANONE OXIME%环己酮肟气相贝克曼重排反应产物己内酰胺的精制研究

    Institute of Scientific and Technical Information of China (English)

    谢丽; 程时标; 张树忠; 慕旭宏

    2015-01-01

    以环己酮肟气相贝克曼重排反应得到的粗己内酰胺为原料,采用蒸馏、苯溶解、水萃取、离子交换、加氢和三效蒸发等现有液相贝克曼重排反应产物的精制路线,对气相重排产物粗己内酰胺进行精制研究,考察己内酰胺在各个提纯精制步骤中的纯度、消光值(UV)、挥发性碱值(VB)、高锰酸钾吸收值(PM)和色度等产品质量变化情况.结果表明,气相重排粗产品经过精制后纯度可达到99.950%,产品PM值和色度达到优级品水平,UV值和VB值分别达到一等品和合格品要求.

  9. 离子液体系中催化环己酮肟重排反应的研究%Catalytic Beckamann Rearrangement of Cyclohexanone Oxime into e-caprolactam in Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    李曹龙; 王洪林; 刘光恒

    2004-01-01

    发现由室温离子液体正丁基吡啶氟硼酸盐,异丁基吡啶氟硼酸盐,正戊基吡啶氟硼酸盐,正辛基吡啶氟硼酸盐等和含磷化合物组成的催化体系,可以高效地实现对环己酮肟重排制己内酰胺的反应,此方法具有不再用有机溶剂,反应副产物少等特点,并考察了不同的离子液、不同磷化合物催化剂、离子液的用量、反应温度、反应时间等对反应的转化率和产物分布的影响,以寻找出一最适宜的反应条件.

  10. Amberlyst36磺酸树脂催化环己酮肟液相重排制己内酰胺%Catalysis of liquid phase rearrangement for cyclohexanone oxime to caprolactam over Amberlyst 36 sulfonic acid resin

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    以Amberlyst 36磺酸树脂为绿色催化剂,催化环己酮肟液相Beekmann重排制己内酰胺,考察了溶剂、反应温度、反应时间、环己酮肟浓度、催化剂用量及催化剂的重复使用对Beckmann重排反应的影响.结果表明:适宜的反应条件为Amberlyst 36催化剂0.5g,环己酮肟1.0g,其质量浓度0.1g/mL,溶剂为二甲基亚砜,反应温度110℃,反应时间7h,在此条件下,环己酮肟转化率为93.93%,己内酰胺选择性为87.54%;将催化剂经过再生处理重复使用2次,在相同条件下进行实验,其环己酮肟的转化率为80.43%,己内酰胺的选择性为81.82%,催化剂重复利用较好.

  11. Beckmann rearrangement of cyclohexanone oxime into caprolactam catalyzed with phosphorus pentoxide%P2O5液相催化环己酮肟重排制己内酰胺

    Institute of Scientific and Technical Information of China (English)

    李惠友; 罗和安

    2005-01-01

    研究了以环己酮肟、五氧化二磷(P2O5)、二甲基甲酰胺(DMF)组成的反应体系进行Beckmann重排制备己内酰胺工艺,考察了不同溶剂、催化剂用量、温度、浓度及水分含量对重排反应的影响.结果表明,由DMF、P2O5、少量水组成的反应体系,当P2O5与环己酮肟质量比为(1.0:4.5)~(1.0:5.6),温度为160~170℃,停留时间为0.75~1.00h时,实现环己酮肟Beckmann重排制己内酰胺,转化率达99.5%以上,选择性达94.5%.

  12. SYNTHESIS OF POLYSTYRENE-BLOCK-POLYCAPROLACTAM WITH 1,1-BIS-(1'-NAPHTHYL) ETHYLENE AS A -DEACTIVATING AGENT

    Institute of Scientific and Technical Information of China (English)

    JIANG Rishan; QUIRK, Roderic P.

    1993-01-01

    The insertion of 1,1-bis (1'-naphthyl) ethylene monomer unit into the active polystyrene chain end greatly decreased the reactivity of the active chain end to the carbonyl group, and allowed the polymeric chain end to react only with the double bond in N-methacryloyl caprolactam, resulting in N-acylcaprolactam functionalized polystyrene in 100% conversion. New diblock copolymer of polystyrene with polycaprolactam was synthesized by direct reaction of the functionalized polymer with caprolactam without adding additional alkali metal or their caprolactam salts.

  13. Vapor-phase Beckmann rearrangement of cyclohexanone oxime over solid acid catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y.; Saeki, Y.; Ito, K.

    1978-01-01

    Of various catalysts tested for the conversion of cyclohexanone oxime to epsilon-caprolactam, best results were obtained with the catalyst having the strongest acid sites, silica-alumina, which gave 60% selectivity at 100% conversion at 330/sup 0/C, 0.505 g catalyst hr/mole, and 0.0563 atm cyclohexanone oxime partial pressure. A decline in activity without loss of selectivity was observed for all catalysts as carbonaceous deposits formed with time on stream (e.g., the caprolactam yield on silica-alumina declined to 90% after 120 min and to 35% after 270 min). Pulse reactor tests with silica-alumina with and without preadsorbed caprolactam showed that cyclohexanone oxime adsorbed even more strongly than the strongly adsorbed caprolactam. The mechanism is discussed. Graphs and 21 references.

  14. Mechanistic studies of the vapor-phase Beckmann rearrangement on solid catalysts by in situ solid-state NMR spectroscopy

    OpenAIRE

    Marthala, Venkata Ramana Reddy

    2009-01-01

    Epsilon-Caprolactam, the main product of the Beckmann rearrangement of cyclohexanone oxime, is an intermediate in the manufacture of nylon-6. Currently, most of the industrial plants produce epsilon-caprolactam by the Beckmann rearrangement of cyclohexanone oxime using sulphuric acid or oleum as a homogeneous catalyst. This process has two main disadvantages: (i) The production of uneconomical by-product, such as ammonium sulphate, and (ii) the environmentally unfriendly corrosive reaction me...

  15. Microwave Radiation Promoted Liquid-Phase Beckmann Rearrangement of Cyclohexanone Oxime for Preparing ε-Caprolactam Over P2O5 Catalyst%微波辐射促进P2O5催化液相贝克曼重排制己内酰胺

    Institute of Scientific and Technical Information of China (English)

    程庆彦; 姬亚宁; 王延吉

    2011-01-01

    在微波辐射的条件下,以P2Os为催化剂,开发了液相贝克曼重排制己内酰胺(CPL)的新型工艺.研究了加热方式、催化剂(HsPO4、ZnCl2和P2O5)、反应容器、微波辐射强度、辐射时间、催化剂用量以及溶剂(环己酮、水和N,N-二甲基甲酰胺)对环己酮肟液相贝克曼重排反应的影响.在催化剂P2O5的质量分数为14.0%(0.19 g)、10 mL N,N-二甲基甲酰胺为反应介质、1.153 g环己酮肟、微波辐射强度为280 W、辐射时间为5.0 min的工艺条件下,环己酮肟的转化率能达到98.69%,己内酰胺收率达到95.75%.此外,该工艺操作简单,反应迅速,收率较高,具有潜在的工业化应用前景.

  16. D-72磺酸树脂催化环己酮肟液相贝克曼重排制己内酰胺%Liquid Phase Beckmann Rearrangement of Cyclohexanone Oxime into ε-Caprolactam Catalyzed by D-72 Sulfonic Acid Resin

    Institute of Scientific and Technical Information of China (English)

    游奎一; 曾珍; 王良芥; 刘平乐; 吴剑; 李松; 尹笃林; 罗和安

    2010-01-01

    在以二甲亚砜作溶剂,以D-72固体磺酸树脂为催化剂的两相体系中,实现了由环己酮肟液相贝克曼重排制备己内酰胺的反应.主要考察了环己酮肟在固体酸催化剂上的吸附热力学规律以及溶剂、反应温度、反应时间、催化剂用量以及催化剂的重复使用性等因素对重排反应的影响.结果表明,环己酮肟在磺酸树脂上的等温吸附过程符合Langmuir吸附模型,吸附等温线可用Langmuir等温方程和速率方程来描述.在二甲亚砜溶剂中,当反应温度在130 ℃,催化剂用量为0.5 g(催化剂:环己酮肟=1:2(质量比))的条件下反应6小时,环己酮肟的转化率高达100%,己内酰胺的选择性为86.2%,主要副产物为环己酮.该法对环境无害,反应条件温和,催化剂容易分离和可重复使用等优点.

  17. Two-phase Beckmann Rearrangement of Cyclohexanone Oxime for Preparing ε-Caprolactam in [bmim] [BF4] Ionic Liquids Using PCl3 as Catalyst%[bmim][BF4]离子液体中PCl3催化的液相贝克曼重排

    Institute of Scientific and Technical Information of China (English)

    张伟; 吴巍; 张树忠; 闵恩泽

    2004-01-01

    在1-丁基-3-甲基咪唑四氟硼酸盐([bmim][BF4])与甲苯组成的两相体系中,以三氯化磷(PCl3)为催化剂,实现了由环己酮肟制备己内酰胺的液相贝克曼重排反应,两相体系有利于反应控制和体系取热.研究了环己酮肟用量、PCl3用量、反应时间和反应温度对重排效果的影响.优化反应条件为:2 ml[bmim][BF4],5 ml甲苯,0.3 ml PCl3,5 ml 2 mol/L环己酮肟-甲苯溶液,90℃,反应时间10~30 min.此时,环己酮肟转化率达98.96%,生成己内酰胺的选择性达87.30%,PCl3催化转化数达2.88.生成的大部分己内酰胺在离子液体相.

  18. Determination of GC-MS Method for Compounds in Caprolactam Produced From Cyclohexanecarboxylic Acid-Cyclohexanone, Oxime Process%六氢苯甲酸-环己酮肟联产己内酰胺组合工艺中酰胺液成分的气相色谱-质谱分析

    Institute of Scientific and Technical Information of China (English)

    王秀君; 潘九海; 赵承军; 孙东升; 于广欣

    2004-01-01

      石家庄化纤公司己内酰胺装置是以甲苯为原料,经氧化、加氢、酰胺化、中和、萃取及精制等工序的装置.其基本工艺技术从意大利引进.由于工艺本身的特点,副产物硫铵达3.8吨/吨己内酰胺.该装置设计年产硫氨19万吨,产量较大.……

  19. 分子筛催化环己酮肟气相Beckmann重排制己内酰胺研究新进展%Advance in Vapor-Phase Beckmann Rearrangement of Cyclohexanone Oxime to ε-Caprolactam Catalyzed by Molecular Sieves

    Institute of Scientific and Technical Information of China (English)

    陶伟川; 毛东森; 陈庆龄

    2004-01-01

    介绍了用以代替浓硫酸催化环己酮肟Beckmann重排反应制己内酰胺的各类分子筛催化剂的研究新进展,并对其反应机理、催化剂的失活与再生、反应新工艺进行了阐述.提出进一步提高己内酰胺的选择性将是今后研究的重点.

  20. Preparation of polyamide 6/silica nanocomposites from silica surface initiated ring-opening anionic polymerization

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Polyamide 6/silica nanocomposites were synthesized by in situ ring-opening anionic polymerization of ε-caprolactam in the presence of sodium caprolactamate as a catalyst and caprolactam-functionalized silica as an initiator. The initiator precursor, isocyanate-functionalized silica, was prepared by directly reacting commercial silica with excess toluene 2,4-diisocyanate. This polymerization was found to occur in a highly efficient manner at relatively low reaction temperature (170°C and short reaction times (6 h. FTIR spectroscopy was utilized to follow the introduction and consumption of isocyanate groups on the silica surface. Thermogravimetric analysis indicated that the polyamide 6 was successfully grown from the silica surface. Transmission electron microscopy was utilized to image polymer-functionalized silica, showing fine dispersion of silica particles and their size ranging from 20 to 40 nm.

  1. Development of advanced zeolite catalysts for the vapor phase Beckmann rearrangement of cyclohexanone oxime

    Science.gov (United States)

    Dai, Lian-Xin; Iwaki, Yoshihide; Koyama, Katsuyuki; Tatsumi, Takashi

    1997-11-01

    The vapor phase Beckmann rearrangement of cyclohexanone oxime to ɛ-caprolactam catalyzed by various zeolites was studied. The catalytic performance was greatly affected by both the zeolite structure and diluent solvent. When 1-hexanol was used in place of benzene, the catalytic performance of all catalysts except silicalite-1 was greatly improved. In particular, the selectivity and stability of H-LTL and H-OFF-ERI zeolites remarkably increased; both catalysts exhibited ca. 100% oxime conversion and ɛ-caprolactam selectivity of >95% for 6 h.

  2. Nylon and Chemical Fiber Industry of Shifeng Developing Synchronously

    Institute of Scientific and Technical Information of China (English)

    Du Yinshi

    2012-01-01

    Recently, over 40 people of the investigation group of the 10th Chinese Caprolactam and Nylon Market Forum went to Shifeng Group for visitation and investigation. They learnt the overall general situation of Shifeng Group in details, visited the factory areas such as chemical fiber & tire industrial park and agricultural automobile industrial park, and listened to the development process of Shifeng Group, the present production and future development of such products as nylon chip, nylon yarn and flat chafer fabric under nylon and chemical fiber project, and the market growth in recent two years. The investigation group showed great cooperation intention on the caprolactam project of Shifeng Group.

  3. Industrial Injury Investigation Bureau's first case%产业损害调查局开始第一案

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ The Ministry of Foreign Trade and Economic Co-operation published an announcement in the middle of December, 2001 that it would start the investigation of the anti-dumping of the imported caprolactam from Japan, Belgium, Germany, Netherland and Russia. The State Economic and Foreign Trade Commission will co-operate with related departments of the State Council making investigation on the injury of the caprolactam import to China's domestic industry. This is the first anti-dumping case after the cancellation of the Anti-Dumping Office by the State Economic and Foreign Trade and the establishment of the Industrial Injury Investigation Bureau.

  4. INFLUENCE OF PREPARATION METHODS OF TiO2-ZrO2 ON CONVERSION OF CYCLOHEXANONE OXIME TO CAPROLACTAM OVER B2O3/TiO2-ZrO2 CATALYST%制备方法对B2O3/TiO2-ZrO2催化环己酮肟制己内酰胺的影响

    Institute of Scientific and Technical Information of China (English)

    毛东森; 陈庆龄; 卢冠忠

    2002-01-01

    考察了载体TiO2-ZrO2的制备方法对B2O3/TiO2-ZrO2催化环己酮肟气相Beckmann重排制己内酰胺反应性能的影响.孔径分布和NH3-TPD的测定结果表明,以共沉淀法制备的TiO2-ZrO2为载体所制备的催化剂具有较适宜的孔径分布和酸性,从而对环己酮肟气相Beckmann重排反应制己内酰胺表现出最高的催化活性和选择性.实验结果还表明,TiO2-ZrO2比其它二元复合氧化物更适宜于作为环己酮肟气相Beckmann重排反应B2O3催化剂的载体.

  5. Beckmann rearrangement of ketoximes to lactams by triphosphazene catalyst.

    Science.gov (United States)

    Hashimoto, Masaharu; Obora, Yasushi; Sakaguchi, Satoshi; Ishii, Yasutaka

    2008-04-01

    Triphosphazene, 1,3,5-triazo-2,4,6-triphosphorine-2,2,4,4,6,6-chloride (TAPC), was found to be an efficient catalyst for the Beckmann rearrangement of cyclohexanone oxime and cyclododecanone oxime to epsilon-caprolactam and laurolactam, which are raw materials of nylon-6 and nylon-12, respectively.

  6. The formation of poly(ester–urea) networks in the absence of isocyanate monomers

    NARCIS (Netherlands)

    Zimmermann, Jörg; Loontjens, Ton; Scholtens, B.J.R.; Mülhaupt, Rolf

    2004-01-01

    The polymerization of N,N' carbonylbis (caprolactam) (CBC) and polyol in the presence of alcoholate as catalyst produced cross-linked poly(ester–urea)s via ring opening addition reaction. In contrast to conventional synthetic routes, the use of non-toxic CBC eliminates the need for toxic isocyanate-

  7. MODIFICATION OF NYLON-6 WITH POLYORGANOSILOXANE

    Institute of Scientific and Technical Information of China (English)

    YUAN Qiang; LIU Guomin; LI Guangliang

    1990-01-01

    Nylon-6 has been modified by polyorganosiloxane. It was realized by radical addition of caprolactam to the vinyl group of silicone and anionic polymerization of the monomer in the presence of the silicone macromer. The mechanical properties of the modified plastics are not far from that of the unmodified one whereas its frictional properties are significantly improved.

  8. Advances in Application of New Catalytic Materials in Petroleum Refining and Petrochemicals Production

    Institute of Scientific and Technical Information of China (English)

    He Yigong; Lin Min; Mu Xuhong; Shu Xingtian

    2006-01-01

    This article introduces the solid acid catalyst for isobutene/butylenes alkylation, the HTS Ti/Si zeolite for ammonoxidation of cyclohexanone and the noncrystalline alloy catalyst and magnetically stabilized bed for hydrofining of caprolactam that were developed recently by SINOPEC Research Institute of Petroleum Processing (RIPP).

  9. Oxidations of amines with molecular oxygen using bifunctional gold–titania catalysts

    DEFF Research Database (Denmark)

    Klitgaard, Søren Kegnæs; Egeblad, Kresten; Mentzel, Uffe Vie

    2008-01-01

    Over the past decades it has become clear that supported gold nanoparticles are surprisingly active and selective catalysts for several green oxidation reactions of oxygen-containing hydrocarbons using molecular oxygen as the stoichiometric oxidant. We here report that bifunctional gold–titania c...... new and environmentally benign routes to caprolactam and cyclohexanone oxime, both of which are precursors for nylon-6....

  10. Water Remedial Investigation Report, Version 2.2. Volume 2

    Science.gov (United States)

    1989-03-01

    pesticide OD outside diameter OF degrees Farenheit OXAT oxathiane OX/DITH Combined oxathiane and dithiane PCE tetrnchloroethylene PI plasticity index...TETRACHLOROETHANE UNK565 91565 451 CAPROLACTAM UNK642 91642 1340 UNK UNK647 91647 12.4 UNK UNK654 916S4 1580 UNK UNK672 91672 7400 UNK UNK694 91694

  11. Water Remedial Investigation Report, Version 3.3. Volume 2

    Science.gov (United States)

    1989-07-01

    Farenheit OXAT oxathiane 0 • OX/DITH Combined oxathiane and dithiane PCE tetrachloroethylene PI plasticity index PID photoionization detector S PMO...TIME 10:24 ’ UNKSIS 91515 26.6 ,I ,2-TRICHLOROETHANE UNKS31 91531 39.1 1,1,2,2-TETRACHLOROETHANE UNK565 91565 451 CAPROLACTAM UNK642 91642 1340 UNK

  12. Are reactive thermoplastic polymers suitable for future wind turbine composite materials blades?

    DEFF Research Database (Denmark)

    Raghavalu Thirumalai, Durai Prabhakaran

    2014-01-01

    , it was found that only two potential reactive thermoplastic resin systems qualify for different processing requirements for blade manufacturing. Hence, the article focuses on the issues with the use of reactive polymers like APA-6 (Caprolactam) and CBT (Cyclic Butylene Terephtalate) resin systems for composite...

  13. Microstructure and Properties of Poly(amide urethane)s : Comparison of the Reactivity of α-Hydroxy-ω-O-phenyl Urethanes and α-Hydroxy-ω-O-hydroxyethyl Urethanes

    NARCIS (Netherlands)

    Sharma, Bhaskar; Ubaghs, Luc; Keul, Helmut; Höcker, Hartwig; Loontjens, Ton; Benthem, Rolf van

    2004-01-01

    Poly(amide urethane)s were prepared from ε-caprolactam, amino alcohols, and diphenyl carbonate or ethylene carbonate in three steps. Polycondensation was performed either with α-hydroxy-ω-O-phenyl urethanes or with α-hydroxy-ω-O-hydroxyethyl urethanes; it was found that the reactivity at 90 °C of th

  14. Hierarchically structured monolithic silicalite-1 consisting of crystallized nanoparticles and its performance in the Beckmann rearrangement of cyclohexanone oxime.

    Science.gov (United States)

    Li, Wen-Cui; Lu, An-Hui; Palkovits, Regina; Schmidt, Wolfgang; Spliethoff, Bernd; Schüth, Ferdi

    2005-09-14

    In this study, we present a synthetic pathway for the fabrication of self-supporting zeolite monoliths consisting of crystallized nanoparticles. A resorcinol-formaldehyde-based organic aerogel is used as a template, and silicalite-1 is used as the zeolite example. The silicalite-1 monoliths obtained consist of individual well-defined zeolite nanocrystals with sizes of 30-40 nm. The monoliths exhibit a high mechanical stability and have hierarchical porosity, with micropores within the zeolite particles, a mesopore system formed by the packing of the nanoparticles, and a macropore system on the monolith level. Such monolithic zeolites show high selectivity typically above 80% to epsilon-caprolactam combined with a high rate of reaction of 0.46 g(caprolactame)/(g(catalyst).h) in the Beckmann rearrangement of cyclohexanone oxime.

  15. Synthesis and investigation of protective of certain oxyethylated nitrogen compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kuzinova, T.M.; Altsybeeva, A.I.; Yavshits, G.A.

    1986-05-01

    This paper investigates oxyethylated derivatives of caprolactam and benzotriazole. The inhibiting properties of the oxyethylated products in aqueous salt solutions are examined. The tests determined the degree of protection of U10 steel (KhGT17), M3, copper and S1 lead. The data indicate that the caprolactam itself does not prevent the corrosion of steel or lead and gives only slight protection of copper. The benzotriazole protects copper. The benzotriazole does not protect steel but it does not aggravate the corrosion, and does not prevent lead corrosion. The introduction of oxyethylene groups into the benzotriazole molecule up to a 15:1 ratio improves the protective properties of the products for lead; with higher contents of the oxyethylene groups, the protection decreases.

  16. Amorphous solid dispersions of sulfonamide/soluplus® and sulfonamide/PVP prepared by ball milling

    OpenAIRE

    Healy, Anne,

    2013-01-01

    PUBLISHED The aim of this paper is to investigate the physicochemical properties of binary amorphous dispersions of poorly soluble sulfonamide/polymeric excipient prepared by ball milling. The sulfonamides selected were sulfathiazole (STZ), sulfadimidine (SDM), sulfamerazine (SMZ) and sulfadiazine (SDZ). The excipients were polyvinylpyrrolidone (PVP) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer, commercially known as Soluplus®. Co-milled systems were cha...

  17. Hβ AND MODIFIED Hβ ZEOLITES AS CATALYSTS FOR BECKMANN REARRANGEMENT OF CYCLOHEXANONE OXIME%Hβ及改性Hβ分子筛催化环己酮肟重排制己内酰胺

    Institute of Scientific and Technical Information of China (English)

    章永洁; 王亚权; 卜亿峰; 王莅; 米镇涛; 何菲; 吴魏; 闵恩泽; 傅送保; 朱泽华

    2004-01-01

    The Beckmann rearrangement of cyclohexanone oxime is an important reaction for obtaining ε-caprolactam, the raw material of nylon 6 fibers. Currently, the widely used technologies for the production of cyclohexanone oxime produce large amounts of byproducts. For the Beckmann rearrangement, many solid acid catalysts such as alumina, boria-alumina, and zeolites including Y, those with MFI-structure and β have been studied. However, no generally accepted understanding about the reaction mechanism has been achieved.

  18. POLYCAPROLACTAM MODIFIED BY POLYBENZIMIDAZOLE

    Institute of Scientific and Technical Information of China (English)

    YANG Guisheng; LU Fengcai

    1990-01-01

    Three polycaprolactam samples modified by 0.05 - 0.50% polybenzimidazole (PBI) by weight were prepared. Their structure and mechanical properties were characterized by means of FT- IR, SEM, DTA,density tensile,impact and viscoelastic method. PBI delayed the superimposed polymerization-crystallization process of the activated anionic polymerization of caprolactam. The monomer casting (MC) nylons modified by PBI had lower crystallinities,lower Tg and more nearly perfect spherulites than MCnylon itself, and showed a typical toughening effect.

  19. Solar photonitrosation of cyclohexane

    Energy Technology Data Exchange (ETDEWEB)

    Riffelmann, K.J.; Funken, K.H. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany). Hauptabteilung Energietechnik

    1997-12-31

    The photonitrosation of cyclohexane with nitrosyl chloride (PNC-process) is the central reaction step of photochemical production of {epsilon}-caprolactam. As compared to other, i.e. thermal routes for manufacture of {epsilon}-caprolactam the photochemical synthesis path is the shortest one, economizing the effective use of raw materials by having the highest yield and selectivity. In 1991 the world-wide capacity of {epsilon}-caprolactam was 3.1 mio metric tons/a. Although the photochemical route is most effective as to the materials costs, only 160 000 metric tons (i.e. 5%) were produced via the photochemical path. To provide the light doped high pressure mercury lamps were used. Disadvantages of the conventional PNC-process are strongly corrosive properties of nitrosyl chloride, high power costs and limited lifetime of the lamps. The last two disadvantages may be avoided using sunlight as clean source of photons. A simplified cost study showed that the solar process has a chance to be realized industrially as an alternative to the conventional technique. In this paper results of a project are dealt with aiming at the experimental investigation of the solar PNC-process to demonstrate that cyclohexanone oxime can be produced in a quality as required by the chemical industry. A solar reactor made of titanium was constructed and tested in the high flux solar furnace at the DLR research center, Koeln. Chemical efficiency and selectivity of the reaction, as well as quality of cyclohexanone oxime produced are presented. (orig.)

  20. Catalytic Properties of Mesoporous Silica (FSM-16) for Beckmann Rearrangement of Cyclohexanone Oxime in Gas Phase

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, T. [Shinshu Univ, Nagano (Japan). Department of Chemistry and Material Engineering Facutly of Engineering; Nakajima, T. [Iiyama Electric Co. Ltd., Nagano (Japan); Mishima, S. [Shinshu Univ, Nagano (Japan). Cooperative Research Center

    1997-08-10

    Catalytic properties of FSM-16 (porous silica with the honeycomb structure of uniform mesopores) were investigated for Beckmann rearrangement of cyclohexanone oxime in gas phase at 523-623 K, and were compared with those of other typical solid acid catalysts. FSM-16 was found to be a long-life catalyst and exhibited higher conversion of the oxime than silica-alumina, H-ZSM-5, Na-ZSM-5, HX-zeolite, and {gamma}-alumina. Selectivity for {epsilon}-caprolactam of FSM-16 was 42-25%, which was lower than that of H-ZSM-5 (89%), silica-alumina (77%), and HX-zeolite (74%). The product composition given by FSM-16 was very similar to that by silica gel. FSM-16, which was impregnated with a solution of aluminum nitrate and then calcined at 823 K, exhibited a higher selectivity (54%) for {epsilon}-caprolactam than an original one. The activity of FSM-16 was remarkably decreased when the catalyst was calcined at 1073 K or above. However, the selectivity for {epsilon}-caprolactam scarcely changed. 10 refs., 4 figs., 1 tab.

  1. Thermal reactions of polymer chains with coal structures

    Energy Technology Data Exchange (ETDEWEB)

    P. Straka; J. Nahunkova [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Institute of Rock Structure and Mechanics

    2003-07-01

    The thermal decompositions of polyethylene, polystyrene and polyamide 6 in the presence of coal was studied by DSC and TGA methods and reactions of these polymers with coal were described. Tars and cokes obtained were characterized and mass balance of the process expressed. Polyethylene decomposes by a free radical mechanism and the major products are 1-alkenes, {alpha},{omega}-alkadienes and n-alkanes. In the presence of coal, formed unsaturated products are adsorbed on the inner surface of coal and semicoke. Maximum weight losses of the coal-polyethylene mixture occur at higher temperature in comparison with that from the decomposition of polyethylene alone. Further, thermal reactions of coal with polystyrene were studied. In the range of 410 490{sup o}C a thermal degradation of coal proceeded, simultaneously, with decomposition of polystyrene. Because coal is a strong H-donor, unsaturated products of polystyrene decomposition (mainly styrene) was hydrogenated by coal. Some aromatic products of polystyrene decomposition reacted with the coal tar structures and new aromatics were formed. That is why the conversion time of polystyrene decomposition was much higher in the presence of coal. The yields of tar from copyrolysis with styrene polymers are higher in comparison with pyrolysis of coal alone. Also composition of tar is changed. Finally, reactions of coal with polyamide 6 were investigated. During the thermal degradation of coal the decomposition of polyamide 6 occurs and {epsilon}-caprolactam and the cyclic dimer are formed. The {epsilon}-caprolactam formation is promoted by water and hydrogen from coal degradation as due to high content of hydrogen coal acts as a strong H- and water donor. Under high-temperature conditions of copyrolysis beside a-caprolactam mainly carbon oxides, methane, aliphatic hydrocarbons, simple aromatics and stable oil are formed. 8 refs., 3 figs., 7 tabs.

  2. Modelling migration in multilayer systems by a finite difference method: the spherical symmetry case

    Science.gov (United States)

    Hojbotǎ, C. I.; Toşa, V.; Mercea, P. V.

    2013-08-01

    We present a numerical model based on finite differences to solve the problem of chemical impurity migration within a multilayer spherical system. Migration here means diffusion of chemical species in conditions of concentration partitioning at layer interfaces due to different solubilities of the migrant in different layers. We detail here the numerical model and discuss the results of its implementation. To validate the method we compare it with cases where an analytic solution exists. We also present an application of our model to a practical problem in which we compute the migration of caprolactam from the packaging multilayer foil into the food.

  3. CURE CHARACTERISTICS OF HYDROXYL TERMINATED POLYBUTADIENE PREPOLYMER WITH BLOCKED TOLUENE DIISOCYANATE-Ⅱ

    Institute of Scientific and Technical Information of China (English)

    Prathima Kamath; M. Srinivasan; V. N. Krishnamurthy

    1994-01-01

    Cure characteristics of hydroxyl terminated polybutadiene (HTPB) prepolymer with a variety of blocked toluene diisocyanate (TDI) in the presence of triethylamine (TEA) and chloroacetic acid catalyst are reported. Phenol, thiophenol, p-chlorophenol, p-nitrophenol,p-cresol , resorcinol, naphthols, caprolactam and butylated-hydroxytoluene were used as blocking agents. Viscosity measurements have been carried out using a mixture of HTPB and blocked TDI in cyclohexanone in the presence of the catalysts at 50℃ and 60℃ using Haake rotational viscometer. Viscosity measurements have also been carried out with 50% solids such as ammonium sulphate along with HTPB and TDI adduct.

  4. Polyamide-6 Polymerization in the VK Tube Reactor with Baffle Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Xia-qin; TANG Zhi-lian

    2002-01-01

    The melt flow mechanism of polyamide-6 (PA6) was simulated with the mathematical flow model and tested by Particle Image Velotrimitry (PIV). The complete mathematical model for PA6 polymerization while flowing through the VK tube reactor was established according to PA6 hydrolytic polymerization kinetics. The characteristic data such as residence time, caprolactam conversion and the degree of polymerization (D. P.), at every stage of polymerization reaction and at every point of the VK tube were presented for the melt flowing through ten alternate conical baffles in VK tube.

  5. Pyrolysis of brown coal mixed with heavy products of coal and petroleum processing

    Energy Technology Data Exchange (ETDEWEB)

    Vikhorev, A.A.; Syroezhko, A.M.; Proskuryakov, V.A.; Akhmedov, N.A.

    1987-03-01

    Investigates effect of various additives on yield of liquid product from pyrolysis of Kansk-Achinsk (Berezovsk deposit) brown coal mixed with organic additives: waste from caprolactam plant consisting mostly of saturated oxygen containing compounds and mono- and di-carboxylic acid esters, waste from sabatic acid plant consisting predominantly of unsaturated acids, distillation residue of synthetic fatty acids, heavy residue from Arlansk oil refineries containing mainly condensed naphtheno-aromatic systems and heavy tar from rapid pyrolysis of Kansk-Achinsk coal. Finds that joint pyrolysis of brown coal with organic additives increases yield of liquid products and that intensive decomposition begins at lower temperatures. 4 refs.

  6. Acetylenic polymers for hair styling products.

    Science.gov (United States)

    Martiny, S

    2002-06-01

    This paper looks at the basic requirements of hair styling products from a consumer's perspective before moving onto a very brief outline of the various chemistries available to the formulator. It then discusses the manufacture of vinyl pyrrolidone from acetylene. The properties of polyvinyl pyrrolidone are described, followed by the features and benefits of some vinyl pyrrolidone copolymers and terpolymers. The instrumental analysis of the hold, flexibility, tack and combing properties of polymer films is discussed in some detail, along with the effect of application type on these measurable properties concentrating upon vinyl caprolactam/vinyl pyrrolidone/dimethylaminopropyl methacrylamide acrylates copolymer.

  7. Synthesis and characterization of PEG-P(MAA-SS-VCL) nanoparticles

    Science.gov (United States)

    Yu, L. L.; Yang, K.; Mu, R. H.; Zhang, N.; Su, L.

    2016-07-01

    The PEG-P(MAA-SS-VCL) nanoparticles were obtained using disulfide containing dimethacrylate (SS) as cross-linking agent, using polyethylene glycol methyl acrylate (PEGMA), N-Vinyl-ε-caprolactam (VCL), and methacrylic acid (MAA) as monomers via homogeneous polymerization in aqueous. The PEG-P(MAA-SS-VCL) nanoparticles were characterized by FT-IR and TGA. The particle size and morphology variation in different environments were detected by dynamic light scattering (DLS) and scanning electron microscopy (SEM). It is the very method that PEG-P(MAA-SS-VCL) nanoparticles can be obtained in this study.

  8. Direct atomic absorption determination of cadmium and lead in strongly interfering matrices by double vaporization with a two-step electrothermal atomizer

    Science.gov (United States)

    Grinshtein, Ilia L.; Vilpan, Yuri A.; Saraev, Alexei V.; Vasilieva, Lubov A.

    2001-03-01

    Thermal pretreatment of a sample using double vaporization in a two-step atomizer with a purged vaporizer makes possible the direct analysis of samples with strongly interfering matrices including solids. A porous-graphite capsule or a filter inserted into the vaporizer is used for solid sample analysis. The technique was used for the direct determination of Cd and Pb in human urine, potatoes, wheat, bovine liver, milk powder, grass-cereal mixtures, caprolactam, bituminous-shale and polyvinyl chloride plastic without chemical modification or any other sample pretreatment.

  9. N,N'-(Hexane-1,6-diylbis(4-methyl-N-(oxiran-2-ylmethylbenzenesulfonamide: Synthesis via cyclodextrin mediated N-alkylation in aqueous solution and further Prilezhaev epoxidation

    Directory of Open Access Journals (Sweden)

    Julian Fischer

    2013-12-01

    Full Text Available N-alkylation of N,N'-(hexane-1,6-diylbis(4-methylbenzenesulfonamide with allyl bromide and subsequent Prilezhaev reaction with m-chloroperbenzoic acid to give N,N'-(hexane-1,6-diylbis(4-methyl-N-(oxiran-2-ylmethylbenzenesulfonamide is described. This twofold alkylation was performed in aqueous solution, whereby α-, and randomly methylated β-cyclodextrin were used as adequate phase transfer catalysts and the cyclodextrin–guest complexes were characterized by 1H NMR and 2D NMR ROESY spectroscopy. Finally, the curing properties of the diepoxide with lysine-based α-amino-ε-caprolactam were analyzed by rheological measurements.

  10. Cyclic oligomers in polyamide for food contact material: quantification by HPLC-CLND and single-substance calibration.

    Science.gov (United States)

    Heimrich, M; Bönsch, M; Nickl, H; Simat, T J

    2012-01-01

    Cyclic oligomers are the major substances migrating from polyamide (PA) food contact materials. However, no commercial standards are available for the quantification of these substances. For the first time the quantification of cyclic oligomers was carried out by HPLC coupled with a chemiluminescence nitrogen detector (CLND) and single-substance calibration. Cyclic monomer (MW = 226 Da) and dimer (MW = 452 Da) of PA66 were synthesised and equimolar N detection of CLND to synthesised oligomers, caprolactam, 6-aminohexanoic acid (monomers of PA6) and caffeine (a typical nitrogen calibrant) was proven. Relative response factors (UVD at 210 nm) referring to caprolactam were determined for cyclic PA6 oligomers from dimer to nonamer, using HPLC-CLND in combination with a UVD. A method for quantification of cyclic oligomer content in PA materials was introduced using HPLC-CLND analysis and caffeine as a single nitrogen calibrant. The method was applied to the quantification of cyclic PA oligomers in several PA granulates. For two PA6 granulates from different manufacturers markedly different oligomer contents were analysed (19.5 versus 13.4 g kg⁻¹). The elution pattern of cyclic oligomers offers the possibility of identifying the PA type and differentiating between PA copolymers and blends.

  11. Production of continuous fiber thermoplastic composites by in-situ pultrusion

    Science.gov (United States)

    Epple, S.; Bonten, C.

    2014-05-01

    The constructive design in the automotive industry, but also in many other industrial sectors has changed steadily over the past decades. It became much more complex due to e.g. increased use of hybrid materials. Combined with the desire to minimize the weight of vehicles and thus the CO2 emissions, the use of low density materials and especially fiber-reinforced plastics is increasing. E.g. Continuous fiber thermoplastic composites are used to reinforce injection molded parts. Low viscosity monomers like caprolactam, which is used to produce polyamide 6 by anionic polymerization are able to easily impregnate and penetrate the textile reinforcement. After wetting the fibers, the ring-opening polymerization starts and the matrix is becoming a polymer. At IKT, a method based on the RIM process (reaction injection molding) was developed to produce continuous fiber thermoplastic composites with high contents of continuous glass fibers. The anionic polymerization of polyamide 6 was now combined with the pultrusion process. Continuous glass fibers are pulled through a mold and wetted with caprolactam (including activator and catalyst). After the material polymerized in the mould, the finished continuous fiber thermoplastic composites can be pulled out and is finally sawn off.

  12. [Research on structure of MC-nylon 6/aramid composites by spectroanalysis method].

    Science.gov (United States)

    Wang, Can-Yao; Zheng, Yu-Ying

    2008-01-01

    The Kevlar fiber, treated with toluene-2,4-diisocyanate and caprolactam, was used to reinforce MC nylon 6. XPS showed the change in chemical components and spectra after fiber was treated. IR showed that the spectra of Kevlar fiber and MC-nylon 6 were incorporated purely when they were mixed, while the treated Kevlar fiber provided the activation in the ring-opening polymerization of caprolactam, and the amide groups of graft chains could form strong hydrogen bonds with matrix. These graft chains and hydrogen bonds would contribute to improving interfacial bonding between MC-nylon 6 and Kevlar fiber. XRD indicated that the induction of Kevlar fiber had no effect on the cryastalline style of MC-nylon 6 obviously, however, the crystals had better seasonal structure. The crystals of MC-nylon 6/Kevlar fiber composites were more perfect than that of MC-nylon 6/Kevlar untreated fiber composites with the same amount of Kevlar fiber. The increase of Kevlar fiber contributed to forming perfect a spherulite when the mass concentration of Kevlar fiber was less than 2%, however, the more the Kevlar fiber, the less the content of a spherulite when the mass concentration of Kevlar fiber was more than 2%.

  13. Reacción tisular a materiales de sutura no absorbibles en piel de equinos Tissue reaction to nonabsorbable suture materials in horse skin

    Directory of Open Access Journals (Sweden)

    F Maldonado

    2006-01-01

    Full Text Available Se evaluó clínica e histológicamente el grado de reacción tisular frente a cuatro materiales de sutura no absorbibles (lino, nylon, caprolactam polimerizado y polipropileno, implantados en la piel de 8 equinos. Se determinó clínicamente el edema provocado y la ausencia o presencia de exudado a los 5 y 10 días de haber sido implantados los materiales de sutura, además al 10º día se realizó una biopsia para determinar histológicamente el grado de reacción tisular. Los resultados obtenidos mostraron que el lino causó un mayor edema al día 5, mientras que al día 10 el nylon y caprolactam provocaron un menor de edema. Con respecto a la presencia o ausencia de exudado, al día 5 la sutura de nylon fue la única que no presentó exudado en ninguno de los 8 ejemplares, sin embargo, al día 10, salvo un ejemplar que presentó exudado en todos los materiales, el nylon, caprolactam y polipropileno no presentaron exudado. En cuanto a la evaluación histológica tanto el nylon como el caprolactam mostraron menor grado de reacción tisular. En conclusión, el lino resultó tener el mayor grado de reacción tisular durante el presente estudio, y el nylon si bien es similar al caprolactam y polipropileno respecto a la reacción tisular, causó una menor cantidad de equinos con presencia de exudado que los otros materiales utilizados.The degree of tissue reaction of 4 nonabsorbable suture materials (linen, nylon, polymerized caprolactum and polypropylene implanted into health skin of 8 horses was clinically and histologically evaluated. Cutaneous oedema and absence or presence of the exudation were clinically evaluated 5 and 10 days following suture material implantation. Biopsies were taken to histologically evaluate tissue reaction at 10 days. The results obtained showed that linen caused more oedema by the 5th day, whereas the nylon and caprolactum had less oedema on the 10th day. With respect to the presence or absence of exudation, nylon was

  14. Is the Beckmann rearrangement a concerted or stepwise reaction? A computational study.

    Science.gov (United States)

    Yamabe, Shinichi; Tsuchida, Noriko; Yamazaki, Shoko

    2005-12-23

    [reaction: see text] RB3LYP calculations were performed on the Beckman rearrangement by the use of three substrates, acetone oxime (1), acetophenone oxime (2), and cyclohexanone oxime (3). Acidic solvents were modeled by H+ (CH3COOH)3 and H3O+ (H2O)6, and reaction paths were determined precisely. For 1, a two-step process involving a sigma-type cationic complex was obtained. For 2, a three-step process with pi- and sigma-type complexes was found in H+ (CH3COOH)3 and a two-step process involving a sigma-type cationic complex was obtained in H3O+ (H2O)6. However, for 3, a concerted process without pi and sigma complexes was calculated, which leads to the product, epsilon-caprolactam. Three different mechanisms were explained in terms of FMO theory.

  15. Idea of environmental catalyst and its application; Kankyo shokubai no hasso to sono riyo

    Energy Technology Data Exchange (ETDEWEB)

    Inumaru, K. [The University of Tokyo, Tokyo (Japan)

    1997-10-20

    The catalyst creating environmental conservation and comfortable environment is generally named an `environmental catalyst (EC).` EC is roughly classified into direct and indirect type ECs. Purification catalysts for automobile exhaust gas, and catalysts for chemical production process are under investigation as direct and indirect type ECs, respectively. The catalyst was found which can remove NOx under the coexistence of oxygen by using hydrocarbon as reductant. In addition, the practical exhaust gas purification catalyst was also developed for lean-burn engines by combining noble metal catalysts with NOx absorbing materials or zeolite superior in reductant adsorbing power. {epsilon}-caprolactam as raw material of nylon 6 is synthesized from cyclohexanoneoxime through Beckmann` rearrangement reaction. Zeolite system solid catalysts using no ammonia are under investigation. An environment-friendly synthesis method using not phosgene but catalyst was proposed for production of dimethyl carbonate. How to utilize catalysts for global material circulation remains unsolved for the future study. 5 refs.

  16. Beckmann rearrangement of 15N-cyclohexanone oxime on zeolites silicalite-1, H-ZSM-5, and H-[B]ZSM-5 studied by solid-state NMR spectroscopy.

    Science.gov (United States)

    Marthala, V R Reddy; Jiang, Yijiao; Huang, Jun; Wang, Wei; Gläser, Roger; Hunger, Michael

    2006-11-22

    By means of solid-state 15N NMR spectroscopy, evidence for the formation of nitrilium ions as intermediates of the Beckmann rearrangement of 15N-cyclohexanone oxime to epsilon-caprolactam on silicalite-1, H-ZSM-5, and H-[B]ZSM-5 is reported. The zeolites under study are characterized by different acid strengths (silicalite-1 < H-[B]ZSM-5 < H-ZSM-5). Depending on the nature of catalytically active surface OH groups, reactant and product molecules exist in the nonprotonated or protonated state. In addition, formation of byproducts such as 5-cyano-1-pentene and epsilon-aminocapric acid as a result of dehydration and hydrolysis of the reactant and product molecules, respectively, were observed.

  17. Design of Highly Selective Platinum Nanoparticle Catalysts for the Aerobic Oxidation of KA-Oil using Continuous-Flow Chemistry.

    Science.gov (United States)

    Gill, Arran M; Hinde, Christopher S; Leary, Rowan K; Potter, Matthew E; Jouve, Andrea; Wells, Peter P; Midgley, Paul A; Thomas, John M; Raja, Robert

    2016-03-01

    Highly active and selective aerobic oxidation of KA-oil to cyclohexanone (precursor for adipic acid and ɛ-caprolactam) has been achieved in high yields using continuous-flow chemistry by utilizing uncapped noble-metal (Au, Pt & Pd) nanoparticle catalysts. These are prepared using a one-step in situ methodology, within three-dimensional porous molecular architectures, to afford robust heterogeneous catalysts. Detailed spectroscopic characterization of the nature of the active sites at the molecular level, coupled with aberration-corrected scanning transmission electron microscopy, reveals that the synthetic methodology and associated activation procedures play a vital role in regulating the morphology, shape and size of the metal nanoparticles. These active centers have a profound influence on the activation of molecular oxygen for selective catalytic oxidations.

  18. Simulation of nylon 6 polymerization in tubular reactors with recycle

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.K.; Kunzru, D.; Kumar, A.; Agarwal, K.K.

    1983-05-01

    In the hydrolytic polymerization of epsilon-caprolactam, the ring opening of the monomer is much slower than the polyaddition reaction. Hence, the mixing of aminocaproic acid to the feed results in a faster conversion of the monomer. Industrially, this fact is exploited by using a recycle stream. An isothermal plug flow reactor (PFR) with a recycle is simulated in this study, using two techniques: the method of successive substitutions and Wegstein's method. It is found that, under certain operating conditions, the use of a recycle stream gives higher monomer conversions and lower cyclic dimer concentrations than either a PFR or a homogeneous continuous flow stirred tank reactor (HCSTR), with the degree of polymerization almost the same as that obtained in an HCSTR, and thus offers a considerable advantage. However, when a recycle reactor is coupled with a subsequent flashing operation and a finishing reactor, these advantages are considerably reduced.

  19. Preparation of low-molecular-weight polyamide 6/hydrotalcite intercalated nanocomposites via insitu polymerization

    Directory of Open Access Journals (Sweden)

    2007-02-01

    Full Text Available Low-molecular-weight PA6 (LMW-PA6/hydrotalcite intercalated nanocomposites were prepared via insitu polymerization in the presence of organo-hydrotalcite with alanine as an initiator at 150°C.The results indicated that alanine in the interlayer gallery of hydrotalcite doesn't change the interlayer distance of hydrotalcite, while it can initiate the polymerization of ε-caprolactam. There exsists γ crystalloid of LMW-PA6 in LMW-PA6/hydrotalcite intercalated nanocomposites. The molecular weight distribution of LMW-PA6 in the intercalated nanocomposites have two peaks and the added amounts of organo-hydrotalcite hardly influence molecular weight of LMW-PA6.

  20. Influence of the Near Molecular Vicinity on the Temperature Regulated Fluorescence Response of Poly(N-vinylcaprolactam

    Directory of Open Access Journals (Sweden)

    Anne Enzenberg

    2016-03-01

    Full Text Available A series of new fluorescent dye bearing monomers, including glycomonomers, based on maleamide and maleic esteramide was synthesized. The dye monomers were incorporated by radical copolymerization into thermo-responsive poly(N‑vinyl-caprolactam that displays a lower critical solution temperature (LCST in aqueous solution. The effects of the local molecular environment on the polymers’ luminescence, in particular on the fluorescence intensity and the extent of solvatochromism, were investigated below as well as above the phase transition. By attaching substituents of varying size and polarity in the close vicinity of the fluorophore, and by varying the spacer groups connecting the dyes to the polymer backbone, we explored the underlying structure–property relationships, in order to establish rules for successful sensor designs, e.g., for molecular thermometers. Most importantly, spacer groups of sufficient length separating the fluorophore from the polymer backbone proved to be crucial for obtaining pronounced temperature regulated fluorescence responses.

  1. Analysis of migrants from nylon 6 packaging films into boiling water.

    Science.gov (United States)

    Barkby, C T; Lawson, G

    1993-01-01

    Ultra-violet spectrophotometry (UV), high performance liquid chromatography (HPLC) and liquid chromatography coupled to mass spectroscopy (LC-MS) were used to identify and quantify oligomers extracted with boiling water from two different nylon 6 films used in boil-in-bag food packaging. The results indicated the loss of up to 1.5% of the original nylon film weight, into the boiling water, as caprolactam and cyclic oligomers up to the nonamer. Extraction time, thickness and type of film used, were found to be parameters which affected the levels of these migrants. These results will be relevant to situations in which food is cooked in the water used to heat the pouch contents.

  2. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.

    Science.gov (United States)

    Khanal, S P; Mahfuz, H; Rondinone, A J; Leventouri, Th

    2016-03-01

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

  3. Estimation of kinetics parameters in Beckmann rearrangement of cyclohexanone oxime using genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    WU Jian; LI Zhong; LUO He-an

    2006-01-01

    Beckmann rearrangement mechanism of cyclohexanone oxime, based on the characteristic of self-catalyzed reaction and polymorphism was proposed. According to the suggested mechanism, the basic approach was the rearrangement of OXH+ while the SO3 acts as dehydrating agent and OXSO3 can turn to CPLSO3 ultimately. Considering self-catalyzed reaction between OXSO3 and CPLH+ , kinetic model for Beckmann rearrangement was established. Corresponding parameters were estimated by using float genetic algorithm (GA) and simulation results agree well with the experimental data below -19.3℃. Industrial equipment was simulated and analyzed. Effects of key process parameters such as molar ratio of sulfuric acid to oxime and circulation ratio on the residual oxime are also discussed. The results show that the caprolactam exists as CPLH+ finally in oleum and the minimum molecular ratio of sulfuric acid to oxime can be 0.5 theoretically.

  4. Estimativa da incerteza de medição: estudo de caso no ensaio de migração de ε-caprolactama com determinação por CG-DIC

    Directory of Open Access Journals (Sweden)

    Fabio Silvestre Bazilio

    2012-01-01

    Full Text Available The estimation of measurement uncertainty of an analytical result is an important tool to be applied for compliance to ISO IEC 17025. Through the available guides it is possible to establish procedures and criteria for the estimation of measurement uncertainty. This paper presents a case study on the estimation of measurement uncertainty in migration the test of ε-caprolactam from the polyamide 6 packages to fatty foods with determination by GC-FID. The calculation methodology used for the estimation of measurement uncertainty for the migration test was developed based on the guides EURACHEM / CITAC and ISO GUM, taking into account relevant aspects of the migration test. The expanded uncertainty estimated was approximately 23% of the concentration of migration.

  5. Role of Crk Adaptor Proteins in Cellular Migration and Invasion in Human Breast Cancer

    Science.gov (United States)

    2009-03-01

    0.0001349 1.280209 0.00657 cholesterol 25- hydroxylase ZNF539 2.225650467 0.0042638 1.295457 0.03133 zinc finger protein 254 PRSS7 2.233104326 0.0239284...4.98281  6.27E‐07  Toll‐like receptor signaling pathway  ‐3.51463  0.00044  Caprolactam degradation  ‐0.99768  0.318433  Phenylalanine , tyrosine and...Escherichia coli infection – EHEC  ‐1.38214  0.166928  Phenylalanine  metabolism  ‐2.08135  0.037401  Pathogenic Escherichia coli infection – EPEC  ‐0.48134

  6. Preparation and characterization of functionalized single walled carbon nanotubes (fSWCNT)/ Hydroxyapatite (HAp)-Nylon hybridized composite biomaterial to study the mechanical properties

    Science.gov (United States)

    Khanal, Suraj; Leventouri, Theodora; Mahfuz, Hassan; Rondinone, Adam

    2014-03-01

    Synthetic hydroxyapatite (HAp) bears poor mechanical properties that limit its applicability in orthopedics. We study the possibility of overcoming such limitations by incorporating functionalized single walled carbon nanotubes (fSWCNT) in a biocompatible/bioactive nano-composite. We present results from synthesis and characterization of samples prepared under different processing parameters. Ultra sonication method was to disperse functionalized single walled carbon nanotubes (fSWCNT) in HAp followed by a simple hot assorting method to incorporate with polymerized ɛ-caprolactam. The fracture toughness of the composite materials was tested in compliance with the ASTM D-5045 standard. We have found that while the fracture toughness strongly depends on the processing parameters, a value comparable to the one for cortical bone is achieved. Mechanical properties, electron microscopy and crystal structure properties of the composite materials will be discussed.

  7. Micro-scale prediction method for API-solubility in polymeric matrices and process model for forming amorphous solid dispersion by hot-melt extrusion.

    Science.gov (United States)

    Bochmann, Esther S; Neumann, Dirk; Gryczke, Andreas; Wagner, Karl G

    2016-10-01

    A new predictive micro-scale solubility and process model for amorphous solid dispersions (ASDs) by hot-melt extrusion (HME) is presented. It is based on DSC measurements consisting of an annealing step and a subsequent analysis of the glass transition temperature (Tg). The application of a complex mathematical model (BCKV-equation) to describe the dependency of Tg on the active pharmaceutical ingredient (API)/polymer ratio, enables the prediction of API solubility at ambient conditions (25°C). Furthermore, estimation of the minimal processing temperature for forming ASDs during HME trials could be defined and was additionally confirmed by X-ray powder diffraction data. The suitability of the DSC method was confirmed with melt rheological trials (small amplitude oscillatory system). As an example, ball milled physical mixtures of dipyridamole, indomethacin, itraconazole and nifedipine in poly(vinylpyrrolidone-co-vinylacetate) (copovidone) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) were used.

  8. Recognizing a limitation of the TBLC-activated peroxide system on low-temperature cotton bleaching.

    Science.gov (United States)

    Chen, Wenhua; Wang, Lun; Wang, Dong; Zhang, Jingjing; Sun, Chang; Xu, Changhai

    2016-04-20

    In this study, cotton was bleached at low temperatures with an activated peroxide system which was established by incorporating a bleach activator, namely, N-[4-(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC) into an aqueous solution of hydrogen peroxide (H2O2). Experimental results showed that the bleaching performance was unexpectedly diminished as the TBCC concentration was increased over the range of 25-100g/L. Kinetic adsorption experiment indicated that this was most likely ascribed to the adsorptive interactions of TBCC and the in situ-generated compounds with cotton fibers. Such a limitation was especially fatal to cold pad-batch bleaching process of cotton in which a high TBCC concentration was often required. The results of this study may stimulate further research to avoid or overcome the limitation of the TBCC-activated peroxide system on low-temperature cotton bleaching.

  9. Biosynthesis of terephthalic acid, isophthalic acid and their derivatives from the corresponding dinitriles by tetrachloroterephthalonitrile-induced Rhodococcus sp.

    Science.gov (United States)

    He, Yu-Cai; Wu, Ya-Dong; Pan, Xue-He; Ma, Cui-Luan

    2014-02-01

    The nitrilase from Rhodococcus sp. CCZU10-1 catalyses the hydrolysis of dinitriles to acids without the formation of amides and cyanocarboxylic acids. It was induced by benzonitrile and its analogues (tetrachloroterephthalonitrile > ε-caprolactam > benzonitrile > phenylacetonitrile), and had activity towards aromatic nitriles (terephthalonitrile > tetrachloroterephthalonitrile > isophthalonitrile > tetrachloroisophthalonitrile > tetrafluoroterephthalonitrile > benzonitrile). After the optimization, the highest nitrilase induction [311 U/(g DCW)] was achieved with tetrachloroterephthalonitrile (1 mM) in the medium after 24 h at 30 °C after optimum enzyme activity was at pH 6.8 and at 30 °C. Efficient biocatalyst recycling was achieved by cell immobilization in calcium alginate, with a product-to-biocatalyst ratios of 776 g terephthalic acid/g DCW and 630 g isophthalic acid/g DCW.

  10. Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

    KAUST Repository

    Behenna, Douglas C.

    2011-12-18

    The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures. © 2012 Macmillan Publishers Limited. All rights reserved.

  11. Chemical engineering of the single-walled carbon nanotube-nylon 6 interface.

    Science.gov (United States)

    Gao, Junbo; Zhao, Bin; Itkis, Mikhail E; Bekyarova, Elena; Hu, Hui; Kranak, Verina; Yu, Aiping; Haddon, Robert C

    2006-06-14

    We report an approach to the chemical engineering of the single-walled carbon nanotube (SWNT)-polymer interfacial interaction in a nylon 6 graft copolymer composite which is based on the degree of SWNT functionality. Continuous fibers are drawn from composites fabricated from the in situ polymerization of caprolactam with SWNTs possessing a range of carboxylic acid (SWNT-COOH) and amide (SWNT-CONH(2)) functionalities. Mechanical performance evaluation of the composite fibers shows that a high concentration of the carboxylic acid functional groups leads to a stronger SWNT-nylon interfacial interaction, as reflected in greater values of the Young's modulus and mechanical strength. Replacement of the COOH group by CONH(2) in the SWNT starting material changes the grafting polymerization chemistry, thereby leading to the covalent attachment of longer graft copolymer chains to the SWNTs, and alters the composite morphology while increasing the composite flexibility and toughness.

  12. Three-dimensional nonwoven scaffolds from a novel biodegradable poly(ester amide) for tissue engineering applications.

    Science.gov (United States)

    Hemmrich, Karsten; Salber, Jochen; Meersch, Melanie; Wiesemann, Ute; Gries, Thomas; Pallua, Norbert; Klee, Doris

    2008-01-01

    Biodegradable polyesters are established biomaterials in medicine due to their chemical characteristics and options for material processing. A main problem, however, is the release of acid degradation products during biodegradation with severe local pH-drops and inflammatory reactions. Polyesteramides, in contrast, show a less prominent pH-drop during degradation. In this study, we developed a simple, reproducible synthesis of the poly(ester amide) (PEA) type C starting from epsilon-caprolactame, 1,4-butanediol, and adipic acid in a one-batch two-step reaction and conducted the manufacturing of PEA-derived 3D textile scaffolds applicable for tissue engineering purposes. The thermal and mechanical properties of PEA-type C were analysed and the structural conformity of different batches was confirmed by NMR spectroscopy and size exclusion chromatography. The polymer was formed into nonwovens by textile manufacturing. Cytotoxicity tests and X-ray photoelectron spectroscopy (XPS) were used to analyze the effect of scaffold extraction before cell seeding. The manufactured carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. The production of PEA type C successfully occurred via simultaneous ring-opening polymerization of epsilon-caprolactame and polycondensation with 1,4-butanediol and adipic acid at 250 degrees C under high-vacuum. Soxhlet extraction allowed optimal cleaning of nonwoven scaffolds. Extracted PEA-derived matrices were capable of allowing good adherence, proliferation, and differentiation of preadipocytes. These results are encouraging and guidance towards an optimally prepared nonwoven carrier applicable for clinical use.

  13. RESEARCH OF HIGH HARDNESS POLYAMIDE WAX%高硬度聚酰胺蜡的研制

    Institute of Scientific and Technical Information of China (English)

    张建雨; 刘昱彤; 冯跃跃

    2011-01-01

    实验以乙酸、己内酰胺、十二烷二元酸、己二胺为原料通过直接熔融缩聚法合成了高硬度聚酰胺蜡,并用IR进行了结构表征,考察了反应物料用量,聚合温度和聚合时间对反应的影响.适宜的工艺条件为:n(十二烷二元酸、乙酸)∶n(己二胺)=1∶1,n(乙酸)∶n(十二烷二元酸)=8∶2,w(己内酰胺)=50%~60%,聚合温度190~200℃,聚合时间4~5 h.所得产物具有较低的滴熔点和超高的硬度,针入度为0 mm.%Using acetic acid, caprolactam, 1,12-dodecanedioic acid, 1,6-diaminohexane as raw materials, the high hardness of polyamide wax was synthesized via direct melt polycondensation reaction. The product was characterized by IR and the effects of the amount of reactants, polymerization tem-perature, and reaction time on the product were researched. The optimum conditions were found as follows: the molar ratio of 1,12-dodecanedioic acid or acetic acid to 1, 6-diaminohexane of 1 1: 1, the molar ratio of acetic acid to 1,12-dodecanedioic acid of 8: 2, caprolactam dosage 50%-60% , polymerization temperature 190 - 200 ℃ , and reaction time 4 - 5 h. The nature of the product was good, having a low dropping point and high hardness, with the penetration of 0 mm.

  14. Structure elucidation and quantification of impurities formed between 6-aminocaproic acid and the excipients citric acid and sorbitol in an oral solution using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Schou-Pedersen, Anne Marie V; Cornett, Claus; Nyberg, Nils; Østergaard, Jesper; Hansen, Steen Honoré

    2015-03-25

    Concentrated solutions containing 6-aminocaproic acid and the excipients citric acid and sorbitol have been studied at temperatures of 50°C, 60°C, 70°C and 80°C as well as at 20°C. It has previously been reported that the commonly employed citric acid is a reactive excipient, and it is therefore important to thoroughly investigate a possible reaction between 6-aminocaproic acid and citric acid. The current study revealed the formation of 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid between 6-aminocaproic acid and citric acid by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance spectroscopy (NMR). Less than 0.03% of 6-aminocaproic acid was converted to 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid after 30 days of storage at 80°C. Degradation products of 6-aminocaproic acid were also observed after storage at the applied temperatures, e.g., dimer, trimer and cyclized 6-aminocaproic acid, i.e., caprolactam. No reaction products between D-sorbitol and 6-aminocaproic acid could be observed. 3-Hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid, dimer and caprolactam were also observed after storage at 20°C for 3 months. The findings imply that an oral solution of 6-aminocaproic acid is relatively stable at 20°C at the pH values 4.00 and 5.00 as suggested in the USP for oral formulations. Compliance with the ICH guideline Q3B is expected.

  15. Detailed compositional characterization of plastic waste pyrolysis oil by comprehensive two-dimensional gas-chromatography coupled to multiple detectors.

    Science.gov (United States)

    Toraman, Hilal E; Dijkmans, Thomas; Djokic, Marko R; Van Geem, Kevin M; Marin, Guy B

    2014-09-12

    The detailed compositional characterization of plastic waste pyrolysis oil was performed with comprehensive two-dimensional GC (GC×GC) coupled to four different detectors: a flame ionization detector (FID), a sulfur chemiluminescence detector (SCD), a nitrogen chemiluminescence detector (NCD) and a time of flight mass spectrometer (TOF-MS). The performances of different column combinations were assessed in normal i.e. apolar/mid-polar and reversed configurations for the GC×GC-NCD and GC×GC-SCD analyses. The information obtained from the four detectors and the use of internal standards, i.e. 3-chlorothiophene for the FID and the SCD and 2-chloropyridine for the NCD analysis, enabled the identification and quantification of the pyrolysis oil in terms of both group type and carbon number: hydrocarbon groups (n-paraffins, iso-paraffins, olefins and naphthenes, monoaromatics, naphthenoaromatics, diaromatics, naphthenodiaromatics, triaromatics, naphthenotriaromatics and tetra-aromatics), nitrogen (nitriles, pyridines, quinolines, indole, caprolactam, etc.), sulfur (thiols/sulfides, thiophenes/disulfides, benzothiophenes, dibenzothiophenes, etc.) and oxygen containing compounds (ketones, phenols, aldehydes, ethers, etc.). Quantification of trace impurities is illustrated for indole and caprolactam. The analyzed pyrolysis oil included a significant amount of nitrogen containing compounds (6.4wt%) and to a lesser extent sulfur containing compounds (0.6wt%). These nitrogen and sulfur containing compounds described approximately 80% of the total peak volume for respectively the NCD and SCD analysis. TOF-MS indicated the presence of the oxygen containing compounds. However only a part of the oxygen containing compounds (2.5wt%) was identified because of their low concentrations and possible overlap with the complex hydrocarbon matrix as no selective detector or preparative separation for oxygen compounds was used.

  16. Depolymerization of Nylon 6 in Mixtures of the Ionic Liquid and Water%离子液体与水的混合体系中尼龙6的解聚反应

    Institute of Scientific and Technical Information of China (English)

    阮如意; 陈晋阳; 徐天娇

    2012-01-01

    Depolymerization of nylon6 to ε-caprolactam was carried out in the ionic liquids and water binary mixtures from 150 to 230 ℃.The products of depolymerization were analyzed by means of infrared spectroscopy,differential scanning calorimeter,liquid chromategraphy-mass spectrometry and high performance liquid chromatography.Response surface methodology(RSM),based on three-variable-three-level Box-Behnken design(BBD),was used to determine the effects of the main parameters on nylon 6 depolymerization.A express of Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2 was established to determine the yield of caprolactam at different reaction temperature(A),the ILs' molar ratio(B),and reaction time(C).The optimal conditions for depolymerization was as follows: reaction temperature of 175 ℃,the molar ratio of IL 14.2%,and reaction time of 7.3 h.Under the condition,the yield of ε-caprolactam is 44.4% and the degradation rate of nylon 6 is 88.4%.%在150℃~230℃条件下,以氯化1-丁基-3-甲基咪唑离子液体与水组成的二元混合体系为介质进行尼龙6的解聚研究。固相残余物利用红外光谱和差示扫描量热仪进行分析。液相产物通过液相色谱-质谱联用仪和液相色谱进行定性与定量分析。建立了反应温度(A)、混合体系中离子液体的物质的量分数(B)以及反应时间(C)与ε-己内酰胺回收率(Y)之间的数学模型:Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2,并利用响应曲面法(RSM)确定了解聚的优化工艺条件,即反应温度175℃、离子液体的物质的量分数14.2%及反应时间7.3h,此时ε-己内酰胺的回收率为44.4%、尼龙6的降解率为88.4%。

  17. Application of TS-1 in cyclohexanone ammoximation reaction%应用于环己酮氨肟化反应的TS-1研究进展

    Institute of Scientific and Technical Information of China (English)

    任文杰; 周向葵; 贾会敏; 李识寒; 张卫峰

    2014-01-01

    The ammoximation of cyclohexanone has become an inevitable trend of technological development of producing caprolactam,and the preparation of Titanium Silicalite-1(TS-1) has become the most important technology of the cyclohexanone ammoximation. However,it is rather expensive and difficult to prepare TS-1,which restricts the industrial production of caprolactam and needs further improvement. Focusing on this issue,this paper reviews the preparation of TS-1, including modified TS-1,TS-1 with large particle diameter,TS-1 compounds,the shaping of TS-1, as well as other technology related to the preparation of TS-1. The future development of the cyclohexanone ammoximation shall be aimed to improve the catalytic activity of TS-1,solve the recycling of TS-1 on an industrial scale,improve the stability and yield of TS-1,and reduce the costs.%环己酮氨肟化工艺是己内酰胺新技术发展的必然趋势之一,而钛硅分子筛TS-1的制备是环己酮氨肟化工艺的核心技术。但由于TS-1合成成本昂贵,合成条件苛刻,制备重复性差,制约了工业化的发展,仍需要不断的技术进步。本文针对这一主题,对环己酮氨肟化反应所需的TS-1催化剂的制备包括TS-1的改性、大颗粒TS-1的制备、复合TS-1的制备、TS-1的成型及其他的TS-1制备工艺等技术进行了系统综述。在环己酮氨肟化反应中,提高TS-1的催化活性、解决工业上TS-1的分离和回收难题、提高TS-1制备的稳定性和产量、降低成本等是未来TS-1研究的发展趋势。

  18. Application of Vapor Phase Beckmann Rearrangement of Cyclohexanone Oxime over (Al,B)-MCM-41 Zeolite%(Al,B)-MCM-41分子筛在气相贝克曼重排反应中的应用

    Institute of Scientific and Technical Information of China (English)

    王利军; 王日杰; 杨晓霞; 张东顺

    2012-01-01

    Two series of catalyst were synthesized by the modified fast synthesis method and characterized by XRD, nitrogen physisorption, FT-IR, 27A1 MAS NMR, and NH3-TPD. The catalysts were used for vapor phase Beckmann rearrangement of cyclohexanone oxime. The XRD results indicate that the synthesized catalysts exhibit the typical mesostructural of MCM-41. The FT-IR results conforme that aluminium ( Al) and boron(B) atoms are coordinated in the framework of zeolite. When the mole ratio of Al/B e-quals 0. 5, with increasing the amount of Al and B content, more weak acid sites are produced. And more weak acid sites are favorable to form caprolactam. When the mole ratio of Si/M equals 10, the selectivity of caprolactam increased with increasing B content. The catalyst has low activity by adding B only in the MCM-41. The activity of (Al, B)-MCM-41 is mainly associated with weak acid site.%用改进的快速合成法制备了2个系列的催化剂,并用XRD、N2吸附、FT-IR、27Al MAS、NMR和NH3-TPD等手段对其表征,用环己酮肟气相贝克曼重排反应评价其活性.结果表明,合成的催化剂具有MCM-41的结构,铝和硼进入到分子筛的骨架中.当n(Al)/n(B)的值一定时,随着铝和硼添加量的增多,分子筛的弱酸性位的数量增多,己内酰胺的选择性升高.当添加的铝和硼的总量一定,随着铝含量的减少,相应硼的量增加,己内酰胺的选择性升高.只添加硼时环己酮肟转化率和己内酰胺的选择性均很低.( Al,B)-MCM-41分子筛在气相贝克曼重排反应中的活性主要与骨架中的铝和硼的数量以及弱酸位的数量有关.

  19. Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

    Directory of Open Access Journals (Sweden)

    Palash Sanphui

    2014-03-01

    Full Text Available Acemetacin (ACM is a non-steroidal anti-inflammatory drug (NSAID, which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM, isonicotinamide (INA, and picolinamide (PAM], caprolactam (CPR, p-aminobenzoic acid (PABA, and piperazine (PPZ. The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable

  20. Skeletal Amorphous Nickel Based Alloy Catalysts and Magnetically Stabilized Bed Hydrogenation Technology

    Institute of Scientific and Technical Information of China (English)

    Min Enze

    2004-01-01

    the high mass transfer efficiency.Combining the amorphous alloy catalyst, a novel magnetically stabilized bed demonstration unit was developed in process of purification of caprolactam at Balin Petrochemical in 2000. Compared with slurry reactor, reactor volume is reduced by 50%. The utilization experiences for more than three year show that the process is successful with decreasing energy consumption and increasing economical benefits. During three years, catalyst consumption was reduced by 60% and hydrogenation efficiency increased by a factor of 8~10 times.Based on the above studies, a commercial set with the capacity of purifying caprolactam of 35kt/a has been built up at Shijiazhuang Chemical Fibre Corporation Limited, SINOPEC. An additional commercial plant is under construction and is scheduled to start up in late 2004.

  1. Liquid-Phase Beckmann Rearrangement of Cyelohexanone Oxime Catalyzed by Acidic Ionic Liquid-Zinc Chloride%酸性离子液体-ZnCl2催化环己酮肟液相Beckmann重排反应

    Institute of Scientific and Technical Information of China (English)

    赵江琨; 王荷芳; 王延吉; 赵新强; 张宝泉

    2011-01-01

    在乙腈介质中,由酸性离子液体和ZnCl2组成的催化体系,可以高效地实现对环己酮肟液相Beckmann重排制己内酰胺的反应.反应过程中生成的唯一副产物环己酮,可以通过氨氧化反应生成原料环己酮肟.考察了溶剂种类、反应温度、反应时间、离子液体用量和ZnCl2用量对环己酮肟重排反应性能的影响.确定了适宜的反应条件;HSO3-b-N(CH)3]HSO4 0.5 mmol,ZnCl2 15 mmol,乙腈10 mL,环己酮肟10 mmol,反应温度80℃,反应时间4h.此条件下,环己酮肟转化率达100%,己内酰胺收率为94.9%.利用在线反应红外光谱仪(React IR IC-10)研究了该催化体系下环己酮肟重捧反应机理.%The liquid-phase Beckmann rearrangement of cyclohexanone oxime was effectively realized to prepare e-caprolactam by using acidic ionic liquid-zinc chloride(IL-ZnCl2) catalytic system in acetonitrile. The only by-product, cyclohexanone, could convert back to the raw material, cyclohexanone oxime, by ammoximation reactionThe effects of solvents, reaction temperature, reaction time, the amount of IL, the amount of ZnCl2 on the Beckmann rearrangement were studied. The optimized conditions were:[HSO3-b-N(CH3)3]HSO4 0.5mmol, ZnCl2 15 mmol, acetonitrile 10 mL, cyclohexanone oxime 10 mmol, 80℃, 4 h. The conversation of cyclohexanone oxime can reach 100%, the yield of e-caprolactam can reach 94.9%.The reaction mechanism of cyclohexanone oxime rearrangement over IL-ZnCl2 catalyst was also investigated by React IR IC-10.

  2. Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt.

    Science.gov (United States)

    Sanphui, Palash; Bolla, Geetha; Nangia, Ashwini; Chernyshev, Vladimir

    2014-03-01

    Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR), p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM-INA cocrystal and a binary adduct ACM-PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM-PAM and ACM-CPR, and the piperazine salt ACM-PPZ were solved from high-resolution powder X-ray diffraction data. The ACM-INA cocrystal is sustained by the acid⋯pyridine heterosynthon and N-H⋯O catemer hydrogen bonds involving the amide group. The acid⋯amide heterosynthon is present in the ACM-PAM cocrystal, while ACM-CPR contains carboxamide dimers of caprolactam along with acid-carbonyl (ACM) hydrogen bonds. The cocrystals ACM-INA, ACM-PAM and ACM-CPR are three-dimensional isostructural. The carboxyl⋯carboxyl synthon in ACM-PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM-PPZ salt and ACM-nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM-PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior

  3. Nanopore and nanoparticle catalysts.

    Science.gov (United States)

    Thomas, J M; Raja, R

    2001-01-01

    The design, atomic characterization, performance, and relevance to clean technology of two distinct categories of new nanocatalysts are described and interpreted. Exceptional molecular selectivity and high activity are exhibited by these catalysts. The first category consists of extended, crystallographically ordered inorganic solids possessing nanopores (apertures, cages, and channels), the diameters of which fall in the range of about 0.4 to about 1.5 nm, and the second of discrete bimetallic nanoparticles of diameter 1 to 2 nm, distributed more or less uniformly along the inner walls of mesoporous (ca. 3 to 10 nm diameter) silica supports. Using the principles and practices of solid-state and organometallic chemistry and advanced physico-chemical techniques for in situ and ex situ characterization, a variety of powerful new catalysts has been evolved. Apart from those that, inter alia, simulate the behavior of enzymes in their specificity, shape selectivity, regio-selectivity, and ability to function under ambient conditions, many of these new nanocatalysts are also viable as agents for effecting commercially significant processes in a clean, benign, solvent-free, single-step fashion. In particular, a bifunctional, molecular sieve nanopore catalyst is described that converts cyclohexanone in air and ammonia to its oxime and caprolactam, and a bimetallic nanoparticle catalyst that selectively converts cyclic polyenes into desirable intermediates. Nanocatalysts in the first category are especially effective in facilitating highly selective oxidations in air, and those in the second are well suited to effecting rapid and selective hydrogenations of a range of organic compounds.

  4. Modelling active sites for the Beckmann rearrangement reaction in boron-containing zeolites and their interaction with probe molecules.

    Science.gov (United States)

    Lezcano-González, Inés; Vidal-Moya, Alejandro; Boronat, Mercedes; Blasco, Teresa; Corma, Avelino

    2010-06-28

    Theoretical calculations and in situ solid state NMR spectroscopy have been combined to get insight on the nature of the active sites for the Beckmann rearrangement reaction in borosilicate zeolites. The interaction of a B site in zeolite Beta with a series of probe molecules (ammonia, pyridine, acetone and water) has been modelled and the (15)N and (11)B NMR isotropic chemical shift of the resulting complexes calculated and compared with experimental in situ NMR results. This approach has allowed validation of the methodology to model the adsorption on a zeolite boron site of molecules of varying basicity which are either protonated or non-protonated. The limitation is that theoretical calculations overestimate the effect of molecular adsorption through hydrogen bonds on the calculated isotropic (11)B NMR chemical shift.Theoretical and experimental results on the adsorption of acetophenone and cyclohexanone oximes on zeolite B-Beta indicate that Brønsted acid sites protonate the oximes, changing the boron coordination from trigonal to tetrahedral. Comparison of theoretical and experimental (15)N NMR chemical shifts of the adsorbed amides (acetanilide and epsilon-caprolactam) indicates that they are non-protonated, and the (11)B NMR spectra show that, as expected, boron remains in trigonal coordination with an isotropic delta(11)B(exp) which differs from the calculated value delta(11)B(calc).

  5. Oxidation of primary amines to oximes with molecular oxygen using 1,1-diphenyl-2-picrylhydrazyl and WO3/Al2O3 as catalysts.

    Science.gov (United States)

    Suzuki, Ken; Watanabe, Tomonari; Murahashi, Shun-Ichi

    2013-03-15

    The oxidative transformation of primary amines to their corresponding oximes proceeds with high efficiency under molecular oxygen diluted with molecular nitrogen (O2/N2 = 7/93 v/v, 5 MPa) in the presence of the catalysts 1,1-diphenyl-2-picrylhydrazyl (DPPH) and tungusten oxide/alumina (WO3/Al2O3). The method is environmentally benign, because the reaction requires only molecular oxygen as the terminal oxidant and gives water as a side product. Various alicyclic amines and aliphatic amines can be converted to their corresponding oximes in excellent yields. It is noteworthy that the oxidative transformation of primary amines proceeds chemoselectively in the presence of other functional groups. The key step of the present oxidation is a fast electron transfer from the primary amine to DPPH followed by proton transfer to give the α-aminoalkyl radical intermediate, which undergoes reaction with molecular oxygen and hydrogen abstraction to give α-aminoalkyl hydroperoxide. Subsequent reaction of the peroxide with WO3/Al2O3 gives oximes. The aerobic oxidation of secondary amines gives the corresponding nitrones. Aerobic oxidative transformation of cyclohexylamines to cyclohexanone oximes is important as a method for industrial production of ε-caprolactam, a raw material for Nylon 6.

  6. Metabolic Engineering toward Sustainable Production of Nylon-6.

    Science.gov (United States)

    Turk, Stefan C H J; Kloosterman, Wigard P; Ninaber, Dennis K; Kolen, Karin P A M; Knutova, Julia; Suir, Erwin; Schürmann, Martin; Raemakers-Franken, Petronella C; Müller, Monika; de Wildeman, Stefaan M A; Raamsdonk, Leonie M; van der Pol, Ruud; Wu, Liang; Temudo, Margarida F; van der Hoeven, Rob A M; Akeroyd, Michiel; van der Stoel, Roland E; Noorman, Henk J; Bovenberg, Roel A L; Trefzer, Axel C

    2016-01-15

    Nylon-6 is a bulk polymer used for many applications. It consists of the non-natural building block 6-aminocaproic acid, the linear form of caprolactam. Via a retro-synthetic approach, two synthetic pathways were identified for the fermentative production of 6-aminocaproic acid. Both pathways require yet unreported novel biocatalytic steps. We demonstrated proof of these bioconversions by in vitro enzyme assays with a set of selected candidate proteins expressed in Escherichia coli. One of the biosynthetic pathways starts with 2-oxoglutarate and contains bioconversions of the ketoacid elongation pathway known from methanogenic archaea. This pathway was selected for implementation in E. coli and yielded 6-aminocaproic acid at levels up to 160 mg/L in lab-scale batch fermentations. The total amount of 6-aminocaproic acid and related intermediates generated by this pathway exceeded 2 g/L in lab-scale fed-batch fermentations, indicating its potential for further optimization toward large-scale sustainable production of nylon-6.

  7. Polyesteramide-derived nonwovens as innovative degradable matrices support preadipocyte adhesion, proliferation, and differentiation.

    Science.gov (United States)

    Hemmrich, K; Meersch, M; Wiesemann, U; Salber, J; Klee, D; Gries, Th; Pallua, N

    2006-12-01

    Extended soft tissue defects resulting from injuries or tumor resections are still an unresolved problem in plastic and reconstructive surgery because adequate reconstruction is difficult. Immature adipogenic precursor cells, called preadipocytes, which are located between mature adipocytes in adipose tissue, represent a powerful tool for soft tissue engineering because of their ability to proliferate and differentiate into adipose tissue after transplantation. In previous studies, we compared preadipocyte-loaded hyaluronan or collagen biomaterials and their applicability for adipose tissue engineering. Our findings demonstrated successful de novo formation of adipose tissue in vivo but pore size and stiffness were limiting factors not allowing for sufficient cell distribution in the construct. This study presents a nonwoven made of novel bioabsorbable co-poly(ester amide) based on e-caprolactam, adipic acid, and 1,4-butanediol in an innovative 3-dimensional architecture. The material was formed into nonwovens by textile manufacturing using an aerodynamic web formation process and a needle felting technique. Carriers were seeded with human preadipocytes and examined for cellular proliferation and differentiation. In addition, methods of preparing scaffolds for optimal cell interaction were evaluated. Our findings show that polyesteramide-derived nonwovens allow good adherence, proliferation, and differentiation of preadipocytes. These results are promising guidance toward an optimally designed scaffold for in vivo use.

  8. Graphene quantum dots decorated CdS doped graphene oxide sheets in dual action mode: As initiator and platform for designing of nimesulide imprinted polymer.

    Science.gov (United States)

    Patra, Santanu; Roy, Ekta; Choudhary, Raksha; Tiwari, Ashutosh; Madhuri, Rashmi; Sharma, Prashant K

    2017-03-15

    The present work describes the preparation of a nanohybrid by a combination of the 2D graphene sheet and 0D graphene quantum dots (GQDs). The GQDs were prepared from natural green precursors i.e. carrot juice by the one-step hydrothermal process. To get the maximum fluorescence property from nanohybrid, the graphene sheets were chemically doped with cadmium sulphide (CdS). The as prepared nanohybrid was characterized by means of X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), fluorescence and UV-vis spectroscopic techniques. The nanohybrid was further modified to design a nano-iniferter, which shows dual property i.e. works as polymerization initiator as well as provides platform for synthesis of the nimesulide-imprinted polymer. For designing of imprinted polymer two biocompatible monomers (cystine monomer and N-vinyl caprolactam) were used, which provides biodegradability to the polymer matrix. The imprinted polymer shows a very good selectivity towards the detection of nimesulide with a limit of detection as low as 6.65ngL(-1) (S/N=3). The sensor was also applied for the detection of nimesulide in real samples like human blood serum, plasma and urine samples as well as some pharmaceutical tablets.

  9. Analytical tools for identification of non-intentionally added substances (NIAS) coming from polyurethane adhesives in multilayer packaging materials and their migration into food simulants.

    Science.gov (United States)

    Félix, Juliana S; Isella, Francesca; Bosetti, Osvaldo; Nerín, Cristina

    2012-07-01

    Adhesives used in food packaging to glue different materials can provide several substances as potential migrants, and the identification of potential migrants and migration tests are required to assess safety in the use of adhesives. Solid-phase microextraction in headspace mode and gas chromatography coupled to mass spectrometry (HS-SPME-GC-MS) and ChemSpider and SciFinder databases were used as powerful tools to identify the potential migrants in the polyurethane (PU) adhesives and also in the individual plastic films (polyethylene terephthalate, polyamide, polypropylene, polyethylene, and polyethylene/ethyl vinyl alcohol). Migration tests were carried out by using Tenax(®) and isooctane as food simulants, and the migrants were analyzed by gas chromatography coupled to mass spectrometry. More than 63 volatile and semivolatile compounds considered as potential migrants were detected either in the adhesives or in the films. Migration tests showed two non-intentionally added substances (NIAS) coming from PU adhesives that migrated through the laminates into Tenax(®) and into isooctane. Identification of these NIAS was achieved through their mass spectra, and 1,6-dioxacyclododecane-7,12-dione and 1,4,7-trioxacyclotridecane-8,13-dione were confirmed. Caprolactam migrated into isooctane, and its origin was the external plastic film in the multilayer, demonstrating real diffusion through the multilayer structure. Comparison of the migration values between the simulants and conditions will be shown and discussed.

  10. Initiated chemical vapor deposition of thermoresponsive poly(N-vinylcaprolactam) thin films for cell sheet engineering.

    Science.gov (United States)

    Lee, Bora; Jiao, Alex; Yu, Seungjung; You, Jae Bem; Kim, Deok-Ho; Im, Sung Gap

    2013-08-01

    Poly(N-vinylcaprolactam) (PNVCL) is a thermoresponsive polymer known to be nontoxic, water soluble and biocompatible. Here, PNVCL homopolymer was successfully synthesized for the first time by use of a one-step vapor-phase process, termed initiated chemical vapor deposition (iCVD). Fourier transform infrared spectroscopy results showed that radical polymerization took place from N-vinylcaprolactam monomers without damaging the functional caprolactam ring. A sharp lower critical solution temperature transition was observed at 31°C from the iCVD poly(N-vinylcaprolactam) (PNVCL) film. The thermoresponsive PNVCL surface exhibited a hydrophilic/hydrophobic alteration with external temperature change, which enabled the thermally modulated attachment and detachment of cells. The conformal coverage of PNVCL film on various substrates with complex topography, including fabrics and nanopatterns, was successfully demonstrated, which can further be utilized to fabricate cell sheets with aligned cell morphology. The advantage of this system is that cells cultured on such thermoresponsive surfaces could be recovered as an intact cell sheet by simply lowering the temperature, eliminating the need for conventional enzymatic treatments.

  11. Catalysis for biomass and CO2 use through solar energy: opening new scenarios for a sustainable and low-carbon chemical production.

    Science.gov (United States)

    Lanzafame, Paola; Centi, Gabriele; Perathoner, Siglinda

    2014-11-21

    The use of biomass, bio-waste and CO2 derived raw materials, the latter synthesized using H2 produced using renewable energy sources, opens new scenarios to develop a sustainable and low carbon chemical production, particularly in regions such as Europe lacking in other resources. This tutorial review discusses first this new scenario with the aim to point out, between the different possible options, those more relevant to enable this new future scenario for the chemical production, commenting in particular the different drivers (economic, technological and strategic, environmental and sustainability and socio-political) which guide the selection. The case of the use of non-fossil fuel based raw materials for the sustainable production of light olefins is discussed in more detail, but the production of other olefins and polyolefins, of drop-in intermediates and other platform molecules are also analysed. The final part discusses the role of catalysis in establishing this new scenario, summarizing the development of catalysts with respect to industrial targets, for (i) the production of light olefins by catalytic dehydration of ethanol and by CO2 conversion via FTO process, (ii) the catalytic synthesis of butadiene from ethanol, butanol and butanediols, and (iii) the catalytic synthesis of HMF and its conversion to 2,5-FDCA, adipic acid, caprolactam and 1,6-hexanediol.

  12. On the inherent properties of Soluplus and its application in ibuprofen solid dispersions generated by microwave-quench cooling technology.

    Science.gov (United States)

    Shi, Nian-Qiu; Lai, Hong-Wei; Zhang, Yong; Feng, Bo; Xiao, Xiao; Zhang, Hong-Mei; Li, Zheng-Qiang; Qi, Xian-Rong

    2016-11-16

    Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, or Soluplus(®), is a relatively new copolymer and a promising carrier of amorphous solid dispersions. Knowledge on the inherent properties of Soluplus(®) (e.g. cloud points, critical micelle concentrations, and viscosity) in different conditions is relatively inadequate, and the application characteristics of Soluplus(®)-based solid dispersions made by microwave methods still need to be clarified. In the present investigation, the inherent properties of a Soluplus(®) carrier, including cloud points, critical micelle concentrations, and viscosity, were explored in different media and in altered conditions. Ibuprofen, a BCS class II non-steroidal anti-inflammatory drug, was selected to develop Soluplus(®)-based amorphous solid dispersions using the microwave-quench cooling (MQC) method. Scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Raman spectroscopy (RS), and Fourier transform infrared spectroscopy (FT-IR) were adopted to analyze amorphous properties and molecular interactions in ibuprofen/Soluplus(®) amorphous solid dispersions generated by MQC. Dissolution, dissolution extension, phase solubility, equilibrium solubility, and supersaturated crystallization inhibiting experiments were performed to elucidate the effects of Soluplus(®) on ibuprofen in solid dispersions. This research provides valuable information on the inherent properties of Soluplus(®) and presents a basic understanding of Soluplus(®) as a carrier of amorphous solid dispersions.

  13. Amorphous solid dispersions of piroxicam and Soluplus(®): Qualitative and quantitative analysis of piroxicam recrystallization during storage.

    Science.gov (United States)

    Lust, Andres; Strachan, Clare J; Veski, Peep; Aaltonen, Jaakko; Heinämäki, Jyrki; Yliruusi, Jouko; Kogermann, Karin

    2015-01-01

    The conversion of active pharmaceutical ingredient (API) from amorphous to crystalline form is the primary stability issue in formulating amorphous solid dispersions (SDs). The aim of the present study was to carry out qualitative and quantitative analysis of the physical solid-state stability of the SDs of poorly water-soluble piroxicam (PRX) and polyvinyl caprolactam-polyvinyl acetate-polyethylene-glycol graft copolymer (Soluplus(®)). The SDs were prepared by a solvent evaporation method and stored for six months at 0% RH/6 °C, 0% RH/25 °C, 40% RH/25 °C and 75% RH/25 °C. Fourier transform infrared spectroscopy equipped with attenuated total reflection accessory (ATR-FTIR) and Raman spectroscopy were used for characterizing the physical solid-state changes and drug-polymer interactions. The principal component analysis (PCA) and multivariate curve resolution alternating least squares (MCR-ALS) were used for the qualitative and quantitative analysis of Raman spectra collected during storage. When stored at 0% RH/6 °C and at 0% RH/25 °C, PRX in SDs remained in an amorphous form since no recrystallization was observed by ATR-FTIR and Raman spectroscopy. Raman spectroscopy coupled with PCA and MCR-ALS and ATR-FTIR spectroscopy enabled to detect the recrystallization of amorphous PRX in the samples stored at higher humidity.

  14. Ammoximation of Cyclohexanone to Cyclohexanone Oxime Catalyzed by Titanium Silicalite-I Zeolite in Three-phase System

    Institute of Scientific and Technical Information of China (English)

    刘国清; 吴剑; 罗和安

    2012-01-01

    An innovative green process of producing ε-caprolactam was proposed by integrating ammoximation and Beckmann rearrangement effectively. As a first part of the new process, TS-1 molecular sieve-catalyzed synthesis of cyclohexanone oxime from cyclohexanone, ammonia and hydrogen peroxide was carried out in a batch plant. Cyclohexane was used as the solvent in the three-phase reaction system. The influences of essential process parameters on ammoximation were investigated. Under the reaction conditions as catalyst content of 2.5% (by mass); H 2 O 2 /yclohexanone molar ratio of 1.10; NH 3 /cyclohexanone molar ratio of 2.20; reaction temperature of 343 K; reaction time of 5 h, high conversion of cyclohexanone and selectivity to oxime (both〉99%) were obtained. Thus, the three-phase ammoximation process showed equal catalytic activity as TS-1 but much more convenient and simpler for the separation of catalyst in comparison to the industrial two-phase system with t-butanol used as solvent.

  15. Highly Ordered Mesoporous Metal Oxides as Catalysts for Dehydrogenation of Cyclohexanol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunok; Jin, Mingshi; Kim, Ji Man [Sungkyunkwan University, Suwon (Korea, Republic of)

    2013-08-15

    Cyclohexanone is important intermediate for the manufacture of caprolactam which is monomer of nylron. Cyclohexanone is generally produced by dehydrogenation reaction of cyclohexanol. In this study, highly mesoporous metal oxides such as meso-WO{sub 3}, meso-TiO{sub 2}, meso-Fe{sub 2}O{sub 3}, meso-CuO, meso-SnO{sub 2} and meso-NiO were synthesized using mesoporous silica KIT-6 as a hard template via nano-replication method for dehydrogenation of cyclohexanol. The overall conversion of cyclohexanol followed a general order: meso-WO{sub 3} >> meso-Fe{sub 2}O{sub 3} > meso-SnO{sub 2} > meso-TiO{sub 2} > meso-NiO > meso-CuO. In particular, meso-WO{sub 3} significantly showed higher activity than the other mesoporous metal oxides. Therefore, the meso-WO{sub 3} has wide range of application possibilities for dehydrogenation of cyclohexanol.

  16. Amorphous Nickel Based Alloy Catalysts and Magnetically Stabilized Bed Hydrogenation Technology

    Institute of Scientific and Technical Information of China (English)

    MuXuhong; ZongBaoning; 等

    2002-01-01

    Amorphous nickel based alloy catalysts(denoted as the SRNA series catalysts)were prepared via rapid quenching method followed by alkali leaching and other activation procedures.The physicochemical characterizations show that nickel,the active component in these catalysts,exists in the amorphous state,and the catalyst particles possess many nanosized voids leading to large surface area(the highest is 145m2/g).The evaluation results in some model reactions show that the SRNA series catalysts have 2 to 4 times higher activity and selectivity than conventional Raney Ni catalyst for the hydrogenation of compounds with unsatur-ated functional groups.At present,the SRNA series catalysts have been successfully used in hydrogenation of glucose,hydrogenation of pharmaceutical intermediates and purification of caprolactam.In order to use these catalysts efficiently,a magnetically stabilized bed(MSB) technology has been developed by combining the ferromagnetic property of the catalyst with the good mass transfer characteristics of MSB.The demonstration unit of MSB hydrogenation technology has been set up and has kept running for 2800 hours.The results show that,after running 2800 hours,the catalyst still retained good activity; meanwhile,the hydrogenation effi-ciency had been improved 10 times in comparison with the traditional CSTR process.

  17. Amorphous Nickel Based Alloy Catalysts and Magnetically Stabilized Bed Hydrogenation Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amorphous nickel based alloy catalysts (denoted as the SRNA series catalysts) were prepared viarapid quenching method followed by alkali leaching and other activation procedures. The physicochemicalcharacterizations show that nickel, the active component in these catalysts, exists in the amorphous state, andthe catalyst particles possess many nanosized voids leading to large surface area (the highest is 145m2/g). Theevaluation results in some model reactions show that the SRNA series catalysts have 2 to 4 times higheractivity and selectivity than conventional Raney Ni catalyst for the hydrogenation of compounds with unsatur-ated functional groups. At present, the SRNA series catalysts have been successfully used in hydrogenation ofglucose, hydrogenation of pharmaceutical intermediates and purification of caprolactam. In order to use thesecatalysts efficiently, a magnetically stabilized bed (MSB) technology has been developed by combining theferromagnetic property of the catalyst with the good mass transfer characteristics of MSB. The demonstrationunit of MSB hydrogenation technology has been set up and has kept running for 2800 hours. The results showthat, after running 2800 hours, the catalyst still retained good activity; meanwhile, the hydrogenation effi-ciency had been improved 10 times in comparison with the traditional CSTR process.

  18. Amorphous Nickel Based Alloy Catalysts and Magnetically Stabilized Bed Hydrogenation Technology

    Institute of Scientific and Technical Information of China (English)

    Mu Xuhong; Zong Baoning; Meng Xiangkun; Min Enze

    2002-01-01

    Amorphous nickel based alloy catalysts (denoted as the SRNAseries catalysts) were prepared viarapid quenching method followed by alkali leaching and other activation procedures. The physicochemicalcharacterizations show that nickel, the active component in these catalysts, exists in the amorphous state, andthe catalyst particles possess many nanosized voids leading to large surface area (the highest is 145m2/g). Theevaluation results in some model reactions show that the SRNA series catalysts have 2 to 4 times higheractivity and selectivity than conventional Raney Ni catalyst for the hydrogenation of compounds with unsatur-ated functional groups. At present, the SRNA series catalysts have been successfully used in hydrogenation ofglucose, hydrogenation of pharmaceutical intermediates and purification of caprolactam. In order to use thesecatalysts efficiently, a magnetically stabilized bed (MSB) technology has been developed by combining theferromagnetic property of the catalyst with the good mass transfer characteristics of MSB. The demonstrationunit of MSB hydrogenation technology has been set up and has kept running for 2800 hours. The results showthat, after running 2800 hours, the catalyst still retained good activity; meanwhile, the hydrogenation effi-ciency had been improved 10 times in comparison with the traditional CSTR process.

  19. Solid-state dependent dissolution and oral bioavailability of piroxicam in rats.

    Science.gov (United States)

    Lust, Andres; Laidmäe, Ivo; Palo, Mirja; Meos, Andres; Aaltonen, Jaakko; Veski, Peep; Heinämäki, Jyrki; Kogermann, Karin

    2013-01-23

    The aim of this study was to gain understanding about the effects of different solid-state forms of a poorly water-soluble piroxicam on drug dissolution and oral bioavailability in rats. Three different solid-state forms of piroxicam were studied: anhydrate I (AH), monohydrate (MH), and amorphous form in solid dispersion (SD). In addition, the effect of a new polymeric excipient Soluplus® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer) on oral bioavailability of piroxicam was investigated. Significant differences in the dissolution and oral bioavailability were found between the solid-state forms of piroxicam. Amorphous piroxicam in SD showed the fastest dissolution in vitro and a solid-state transformation to MH in the dissolution medium. Despite the presence of solid-state transformation, SD exhibited the highest rate and extent of oral absorption in rats. Oral bioavailability of other two solid-state forms decreased in the order AH and MH. The use of Soluplus® was found to enhance the dissolution and oral bioavailability of piroxicam in rats. The present study shows the importance of solid-state form selection for oral bioavailability of a poorly water-soluble drug.

  20. Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida

    Directory of Open Access Journals (Sweden)

    Ashvini Chauhan

    2016-06-01

    Full Text Available We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2′,6′-diethylphenyl-N (methoxymethylacetanilide] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(edi-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene and several chloroaromatic compounds.

  1. Soluplus graft copolymer: potential novel carrier polymer in electrospinning of nanofibrous drug delivery systems for wound therapy.

    Science.gov (United States)

    Paaver, Urve; Tamm, Ingrid; Laidmäe, Ivo; Lust, Andres; Kirsimäe, Kalle; Veski, Peep; Kogermann, Karin; Heinämäki, Jyrki

    2014-01-01

    Electrospinning is an effective method in preparing polymeric nanofibrous drug delivery systems (DDSs) for topical wound healing and skin burn therapy applications. The aim of the present study was to investigate a new synthetic graft copolymer (Soluplus) as a hydrophilic carrier polymer in electrospinning of nanofibrous DDSs. Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PCL-PVAc-PEG)) was applied in the nonwoven nanomats loaded with piroxicam (PRX) as a poorly water-soluble drug. Raman spectroscopy, X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy (SEM) were used in the physical characterization of nanofibrous DDSs. According to the SEM results, the drug-loaded PCL-PVAc-PEG nanofibers were circular in cross-section with an average diameter ranging from 500 nm up to 2  µm. Electrospinning stabilized the amorphous state of PRX. In addition, consistent and sustained-release profile was achieved with the present nanofibrous DDSs at the physiologically relevant temperature and pH applicable in wound healing therapy. In conclusion, electrospinning can be used to prepare nanofibrous DDSs of PCL-PVAc-PEG graft copolymer (Soluplus) and to stabilize the amorphous state of a poorly water-soluble PRX. The use of this synthetic graft copolymer can open new options to formulate nanofibrous DDSs for wound healing.

  2. Reactive microencapsulation of carbon allotropes in polyamide shell-core structures and their transformation in hybrid composites with tailored electrical properties

    Directory of Open Access Journals (Sweden)

    F. Oliveira

    2016-02-01

    Full Text Available Polyamide 6 microcapsules (PAMC loaded with 2–10 wt% of different carbon allotropes: carbon black, multiwalled carbon nanotubes, carbon nanofibers and graphite were synthesized via activated anionic polymerization (AAROP of ε-caprolactam in solution performed in the presence of the respective micro- or nanosized loads. The forming high-molecular weight microporous PAMC showed typical diameters of 15–35 µm, the filler particles being entrapped in the core as proven by microscopy methods. The melt processing of the loaded microcapsules produced PA6/C-filler hybrid thermoplastic composites with homogeneous distribution of one or two C-fillers even at loads of up to 10% without any functionalization. The crystalline structure of all PAMC and molded composites was studied by thermal and X-ray diffraction methods focusing on possible structure modification during the transition from PAMC to molded plates. Mechanical tests in tension and electrical conductivity measurements showed that transforming loaded PAMC into composites by melt processing could be a facile and rapid method to fabricate polyamide composites with improved mechanical performance and tailored electrical and dielectric properties.

  3. Evaluation of PEMFC System Contaminants on the Performance of Pt Catalyst via Cyclic Voltammetry: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Macomber, C.; Dinh, H. N.

    2012-07-01

    Using electrochemical cyclic voltammetry as a quick ex-situ screening tool, the impact of the extracted solution and the individual leachable constituents from prospective BOP component materials on the performance and recoverability of the platinum catalyst were evaluated. Taking an extract from Zytel{trademark} HTN51G35HSLR (PPA) as an example, the major leachable organic components are caprolactam and 1,6 hexanediol. While these organic compounds by themselves do poison the Pt catalyst to some extent, such influence is mostly recoverable by means of potential holding and potential cycling. The extracted solution, however, shows a more drastic poisoning effect and it was not recoverable. Therefore the non-recoverable poisoning effect observed for the extracted solution is not from the two organic species studied. This demonstrates the complexity of such a contaminant study. Inorganic compounds that are known poisons like sulfur even in very low concentrations, may have a more dominant effect on the Pt catalyst and the recoverability.

  4. Designing Catalysts for Clean Technology, Green Chemistry, and Sustainable Development

    Science.gov (United States)

    Meurig Thomas, John; Raja, Robert

    2005-08-01

    There is a pressing need for cleaner fuels (free or aromatics and of minimal sulfur content) or ones that convert chemical energy directly to electricity, silently and without production of noxious oxides and particulates; chemical, petrochemical and pharmaceutical processes that may be conducted in a one-step, solvent-free manner and that use air as the preferred oxidant; and industrial processes that minimize consumption of energy, production of waste, or the use of corrosive, explosive, volatile, and nonbiodegradable materials. All these needs and other desiderata, such as the in situ production and containment of aggressive and hazardous reagents, and the avoidance of use of ecologically harmful elements, may be achieved by designing the appropriate heterogeneous inorganic catalyst, which ideally should be cheap, readily preparable and fully characterizable, preferably under in situ reaction conditions. A range of nanoporous and nanoparticle catalysts that meet most of the stringent demands of sustainable development and responsible (clean) technology is described. Specific examples that are highlighted include the production of adipic acid (precursor of polyamides and urethanes) without the use of concentrated nitric acid nor the production of greenhouse gases such as nitrous oxide; the production of caprolactam (precursor of nylon) without the use of oleum and hydroxylamine sulfate; and the terminal oxyfunctionalization of linear alkanes in air. The topic of biocatalysis and sustainable development is also briefly discussed for the epoxidation of terpenes and fatty acid methyl esters; for the generation of polymers, polylactides, and polyesters; and for the production of 1,3-propanediol from corn.

  5. The Role of a Nonribosomal Peptide Synthetase in l-Lysine Lactamization During Capuramycin Biosynthesis.

    Science.gov (United States)

    Liu, Xiaodong; Jin, Yuanyuan; Cui, Zheng; Nonaka, Koichi; Baba, Satoshi; Funabashi, Masanori; Yang, Zhaoyong; Van Lanen, Steven G

    2016-05-03

    Capuramycins are one of several known classes of natural products that contain an l-Lys-derived l-α-amino-ɛ-caprolactam (l-ACL) unit. The α-amino group of l-ACL in a capuramycin is linked to an unsaturated hexuronic acid component through an amide bond that was previously shown to originate by an ATP-independent enzymatic route. With the aid of a combined in vivo and in vitro approach, a predicted tridomain nonribosomal peptide synthetase CapU is functionally characterized here as the ATP-dependent amide-bond-forming catalyst responsible for the biosynthesis of the remaining amide bond present in l-ACL. The results are consistent with the adenylation domain of CapU as the essential catalytic component for l-Lys activation and thioesterification of the adjacent thiolation domain. However, in contrast to expectations, lactamization does not require any additional domains or proteins and is likely a nonenzymatic event. The results set the stage for examining whether a similar NRPS-mediated mechanism is employed in the biosynthesis of other l-ACL-containing natural products and, just as intriguingly, how spontaneous lactamization is avoided in the numerous NRPS-derived peptides that contain an unmodified l-Lys residue.

  6. Electrospun fibers as potential carrier systems for enhanced drug release of perphenazine.

    Science.gov (United States)

    Bruni, Giovanna; Maggi, Lauretta; Tammaro, Loredana; Lorenzo, Rosadele Di; Friuli, Valeria; D'Aniello, Sharon; Maietta, Mariarosa; Berbenni, Vittorio; Milanese, Chiara; Girella, Alessandro; Marini, Amedeo

    2016-09-10

    Solubility represents an important challenge for formulation of drugs, because the therapeutic efficacy of a drug depends on the bioavailability and ultimately on its solubility. Low aqueous solubility is one of the main issues related with formulation design and development of new molecules. Many drug molecules present bioavailability problems due to their poor solubility. For this reason there is a great interest in the development of new carrier systems able to enhance the dissolution of poorly water-soluble drugs. In this work, fibers containing an insoluble model drug and prepared by an electrospinning method, are proposed and evaluated to solve this problem. Two hydrophilic polymers, polyvinylpyrrolidone (Plasdone® K29/32) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) were used to increase the water solubility of perphenazine. The physico-chemical characterization suggests that the drug loaded in the fibers is in the amorphous state. Both polymeric carriers are effective to promote the drug dissolution rate in water, where this active pharmaceutical ingredient is insoluble, due to the fine dispersion of the drug into the polymeric matrices, obtained with this production technique. In fact, the dissolution profiles of the fibers, compared to the simple physical mixture of the two components, and to the reference commercial product Trilafon® 8mg tablets, show that a strong enhancement of the drug dissolution rate can be achieved with the electrospinning technique.

  7. MECHANOMAGNETIC REACTOR FOR ACTIVATION OF ANTICANCER DRUGS

    Directory of Open Access Journals (Sweden)

    Orel V. E.

    2014-02-01

    Full Text Available Mechanomagnetochemical activation can increase the concentration of paramagnetic centers (free radicals in the anticancer drug, for example, doxorubicin that enables to influence its magnetic properties under external electromagnetic field and improve its magnetic sensitivity and antitumor activity. The principles of design and operation of mechanomagnetic reactor for implementation of this technology which includes mechanomagnetochemical activation and electromagnetic radiation of the drug are described in the paper. The methods of vibration magnetometry, electron paramagnetic resonance spectroscopy and high-performance liquid chromatography were used for studying of doxorubicin mechanomagnetic activation effects. The studies have shown that a generator of sinusoidal electromagnetic wave, working chambers from caprolactam, fluoroplastic or organic materials with metal inserts and working bodies made from steel or agate depending on the required doxorubicin magnetic properties are expedient to use in the designed mechanomagnic reactor. Under influence of mechanomagnetochemical activation doxorubicin, which is diamagnetic, acquires the properties of paramagnetic without changing g-factors in the spectra of electron paramagnetic resonance. Mechanomagnetochemical activation of doxorubicin satisfies pharmacopoeia condi tions according to the results of liquid chromatography that points on perspective of this method using in technology of tumor therapy with nanosized structures and external electromagnetic radiation.

  8. Isolation and Quantification of Polyamide Cyclic Oligomers in Kitchen Utensils and Their Migration into Various Food Simulants.

    Science.gov (United States)

    Abe, Yutaka; Mutsuga, Motoh; Ohno, Hiroyuki; Kawamura, Yoko; Akiyama, Hiroshi

    2016-01-01

    Small amounts of cyclic monomers and oligomers are present in polyamide (PA)-based kitchen utensils. In this study, we isolated eight PA-based cyclic monomers and oligomers from kitchen utensils made from PA6 (a polymer of ε-caprolactam) and PA66 (a polymer of 1,6-diaminohexane and adipic acid). Their structures were identified using high-resolution mass spectrometry and 1H- and 13C-nuclear magnetic resonance spectroscopy, and their residual levels in PA-based kitchen utensils and degree of migration into food simulants were quantified by high-performance liquid chromatography/mass spectrometry using purchased PA6 monomer and isolated PA66 monomers, and isolated PA6 and PA66 oligomers as calibration standards. Their total residual levels among 23 PA-based kitchen utensils made from PA6, PA66, and copolymers of PA6 and PA66 (PA6/66) ranged from 7.8 to 20 mg/g. Using water, 20% ethanol, and olive oil as food simulants, the total migration levels of the PA monomers and oligomers ranged from 0.66 to 100 μg/cm2 under most examined conditions. However, the total migration levels of the PA66 monomer and oligomers from PA66 and PA6/66 kitchen utensils into 20% ethanol at 95°C were very high (1,700 and 2,200 μg/cm2, respectively) due to swelling by high-temperature ethanol.

  9. Soluplus Graft Copolymer: Potential Novel Carrier Polymer in Electrospinning of Nanofibrous Drug Delivery Systems for Wound Therapy

    Directory of Open Access Journals (Sweden)

    Urve Paaver

    2014-01-01

    Full Text Available Electrospinning is an effective method in preparing polymeric nanofibrous drug delivery systems (DDSs for topical wound healing and skin burn therapy applications. The aim of the present study was to investigate a new synthetic graft copolymer (Soluplus as a hydrophilic carrier polymer in electrospinning of nanofibrous DDSs. Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PCL-PVAc-PEG was applied in the nonwoven nanomats loaded with piroxicam (PRX as a poorly water-soluble drug. Raman spectroscopy, X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy (SEM were used in the physical characterization of nanofibrous DDSs. According to the SEM results, the drug-loaded PCL-PVAc-PEG nanofibers were circular in cross-section with an average diameter ranging from 500 nm up to 2 µm. Electrospinning stabilized the amorphous state of PRX. In addition, consistent and sustained-release profile was achieved with the present nanofibrous DDSs at the physiologically relevant temperature and pH applicable in wound healing therapy. In conclusion, electrospinning can be used to prepare nanofibrous DDSs of PCL-PVAc-PEG graft copolymer (Soluplus and to stabilize the amorphous state of a poorly water-soluble PRX. The use of this synthetic graft copolymer can open new options to formulate nanofibrous DDSs for wound healing.

  10. Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida

    Science.gov (United States)

    Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y.I.; Stothard, Paul

    2016-01-01

    We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds. PMID:27672405

  11. Application of mixtures of polymeric carriers for dissolution enhancement of oxeglitazar using hot-melt extrusion.

    Science.gov (United States)

    Kalivoda, Adela; Fischbach, Matthias; Kleinebudde, Peter

    2012-12-15

    Hot-melt extrusion was applied to improve the solubility of the poorly water-soluble drug oxeglitazar. Various polymers and their blends were used as carriers: copovidone (COP), polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol copolymer (PVCL-PVAc-PEG) and hypromellose 2910/5 (HPMC). After extrusion, the extrudate was pelletized. The physical state of the drug was assessed using X-ray diffraction and differential scanning calorimetry. The dissolution performance of the extrudates was compared to the physical mixture and pure oxeglitazar. The stability under long-term storage conditions (25 °C/60%rH) was investigated.The solubility of oxeglitazar was improved with all hot-melt extruded formulations: 26-66% of the drug was dissolved and a 1.9-5.0-fold supersaturation was reached with the pelletized extrudates. All extrudates which were assessed for their storage stability showed sufficient product stability. A super-additive effect of COP and HPMC as a polymeric blend was successfully demonstrated as a higher supersaturation and longer time of supersaturation were shown for the ternary blend. Through variations of the ratio COP:HPMC, it was shown that the shape of the dissolution curve is dominated by the polymer with the higher amount in the polymeric blend. If PVCL-PVAc-PEG is applied as single or additional carrier, the initial release rate is drastically reduced.

  12. Dissolution enhancement of poorly water-soluble APIs processed by hot-melt extrusion using hydrophilic polymers.

    Science.gov (United States)

    Maniruzzaman, M; Rana, M M; Boateng, J S; Mitchell, J C; Douroumis, D

    2013-02-01

    The aim of this study was to investigate the efficiency of hydrophilic polymers to enhance the dissolution rate of poorly water-soluble active pharmaceutical ingredients (APIs) processed by hot-melt extrusion (HME). Indomethacin (INM) and famotidine (FMT) were selected as model active substances while polyvinyl caprolactam graft copolymer, soluplus (SOL) and vinylpyrrolidone-vinyl acetate copolymer grades, Kollidon VA64 (VA64) and Plasdone S630 (S630) were used as hydrophilic polymeric carriers. For the purpose of the study, drug-polymer binary blends at various ratios were processed by a Randcastle single screw extruder. The physicochemical properties and the morphology of the extrudates were evaluated through X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Increased drug loadings of up to 40% were achieved in the extruded formulations for both drugs. INM and FMT exhibited strong plasticization effects with increasing concentrations and were found to be molecularly dispersed within the polymer blends. The in vitro dissolution studies showed increased INM/FMT release rates for all formulations compared to that of pure APIs alone.

  13. Application of mixtures of polymeric carriers for dissolution enhancement of fenofibrate using hot-melt extrusion.

    Science.gov (United States)

    Kalivoda, Adela; Fischbach, Matthias; Kleinebudde, Peter

    2012-06-15

    Hot-melt extrusion was applied to improve dissolution behavior of poorly soluble model drug fenofibrate. Blends of polymers were used as carrier: copovidone (COP), polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol copolymer (PVCL-PVAc-PEG) and hypromellose 2910/5 (HPMC). The ratio of fenofibrate to COP remained constantly 1+3 (weighted parts) with varying amounts of PVCL-PVAc-PEG and HPMC. Solid state of fenofibrate was characterized by X-ray diffractometry and differential scanning calorimetry. Dissolution performance was compared to marketed formulations Lipidil and Lipidil-Ter. Stability studies were conducted at 25°C/60%rH. The dissolution rate from extrudates was significantly increased when compared to pure fenofibrate powder or physical mixture of the components. A supersaturation of 7.6-12.1 was reached with the pelletized extrudates. All extrudates were superior to marketed formulations. No recrystallization was observed after 26 weeks of storage for fenofibrate-COP extrudates 1+3 (weighted parts) with or without polymeric additives. Even so, both degree and duration of supersaturation decreased with increasing storage periods with the exception of fenofibrate-HPMC extrudates. Of particular interest is the finding that by adding polymers with differing release characteristics to the drug-carrier mixture, the dissolution performance of hot-melt extruded solid dosage forms can be readily adapted to meet specific requirements.

  14. Sources et marché du sulfate d'ammonium Sources of and Market for Ammonium Sulfate

    Directory of Open Access Journals (Sweden)

    Loussouarn C.

    2006-11-01

    Full Text Available Engrais azoté le plus utilisé dans le monde jusqu'en 1970, le sulfate d'ammonium ne représente plus aujourd'hui que 4 % de la fertilisation azotée. Avec une teneur en azote de 21 % seulement, il a été peu à peu remplacé comme engrais universel par des produits plus concentrés, notamment l'urée et le nitrate d'ammonium. Obtenu pour plus de 40 % comme sous-produit dans la synthèse de monomères comme le caprolactame, l'acrylonitrile ou le méthacrylate de méthyle, et pour près de 10 % dans le traitement des gaz de cokerie, sa production dépend largement des développements du marché des fibres synthétiques, et, dans une moindre mesure, de la sidérurgie et de la métallurgie. Dans les pays développés, où la production est essentiellement fatale, le volume du marché est et sera plus fonction de la disponibilité du sulfate d'ammonium que de la demande ou de facteurs de marché; sa consommation ne résidera plus que dans des applications spécifiques pour lesquelles il sera bien adapté. Par contre, l'intérêt croissant pour compenser le déficit en soufre de certains sols, et les qualités agronomiques propres du sulfate d'ammonium laissent entrevoir la possibilité d'un essor de son utilisation dans certaines régions en voie de développernent. Ammonium sulfate was the most worldwide nitrogenous fertilizer used up to 1970. Today, it makes up only 4% of nitrogenous fertilization. With a nitrogen content of only 21%, it has gradually been replaced as a universal fertilizer by more concentrated products, particularly urea and ammonium nitrate. More than 40% of the ammonium sulfate is obtained as a by-product from the synthesis of monomers such as caprolactam, acrylonitrile or methyl methacrylate, and nearly 10% from coking gas processing. Its production depends extensively on the development of the market for synthetic fibers and, to a lesser extent, on the steel and metallurgical industries. In the industrialized countries

  15. 阴离子原位聚合橡胶改性尼龙6的形态结构%Morphological Structure of Rubber-Modiifed Nylon-6 Prepared by Anionic In-situ Polymerization

    Institute of Scientific and Technical Information of China (English)

    赵洪凯; 王洪里

    2016-01-01

    The rubber modifier was prepared by grafting on hydroxyl-terminated liquid polybutadiene rubber(HTPB) with HDI urea diketone and blocking the isocyanate group with caprolactam,and the liquid rubber-modified nylon-6 resin was prepared by the anionic polymerization. The infrared analysis shows that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB,and then,the rubber-modified nylon copolymer is generated by the anionic polymerization. After the impact section analysis,when the rubber content is higher than 15%,the modified nylon resin shows the obvious ductile fracture,the toluene etching after the brittle failure shows that the rubber which does not participate in the polymerization is increased when the content of the rubber activator is increased,which causes that the micro-phase size of the rubber is increased and the uniformity is reduced. At 180℃,the rubber-modified nylon 6 resin generated by the polymerization showsαcrystal form,and the addition of the rubber does not changed the crystal form of the nylon 6; after the resin is molten and subjected to the cold crystallization rapidly, the crystal form of nylon 6 is mainly metastableγcrystal form,and as the rubber content is increased,αcrystal form is obviously enhanced,which shows that the existence of the rubber phase is beneficial to form the stableαcrystal form.%采用HDI脲二酮接枝端羟基聚丁二烯液体橡胶(HTPB),再用己内酰胺封端异氰酸酯基团,制得橡胶改性剂,通过阴离子聚合制得液体橡胶改性尼龙(PA)6树脂。分析表明,HDI脲二酮接枝到HTPB的羟基上后被己内酰胺成功封端,进而阴离子聚合生成橡胶改性PA6共聚物。冲击断面分析,当橡胶质量分数高于15%以后,改性PA6树脂表现出明显的韧性断裂,脆断后甲苯刻蚀表明,随着橡胶活化剂含量增加,未参与聚合橡胶含量增加,导致橡胶微相尺寸变大且均匀性下降。在180℃

  16. Positively regulated bacterial expression systems.

    Science.gov (United States)

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high-level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC-XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (L-arabinose, L-rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone-related compounds, ε-caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC-XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/P(BAD), RhaR-RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications.

  17. Carbon-supported platinum alloy catalysts for phenol hydrogenation for making industrial chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, S.T.; Song, C.

    1999-07-01

    Phenol is available in large quantities in liquids derived from coal and biomass. Phenol hydrogenation is an industrially important reaction to produce cyclohexanone and cyclohexanol. Cyclohexane, cyclohexene and benzene are obtained as minor products in this reaction. Cyclohexanone is an important intermediate in the production of caprolactam for nylon 6 and cyclohexanol for adipic acid production. In USA, cyclohexanol and cyclohexanone are produced by benzene hydrogenation to cyclohexane over nickel or noble metal catalysts, followed by oxidation of cyclohexane to produce a mixture of cyclohexanol and cyclohexanone. Then cyclohexanol is dehydrogenated in the presence of Cu-Zn catalyst to cyclohexanone. Usually phenol hydrogenation is also carried out by using Ni catalyst in liquid phase. However, a direct single-step vapor phase hydrogenation of phenol to give cyclohexanone selectively is more advantageous in terms of energy savings and process economics, since processing is simplified and the endothermic step of cyclohexanol dehydrogenation can be avoided, as demonstrated by Montedipe and Johnson Matthey using promoted Pd/Al{sub 2}O{sub 3} catalyst. While it is not the purpose of this paper to dwell on the relative merits of these routes, it is necessary to mention that while using monometallic catalysts, generally the problem of catalyst deactivation of sintering as well as coking is frequently encountered. Addition and alloying of noble metal (e.g. Pt) with a second metal can result in a catalyst with better selectivity and activity in the reaction which is more resistant to deactivation. This paper presents the results on the single-step vapor phase hydrogenation of phenol over carbon-supported Pt-M (M=Cr, V, Zr) alloy catalysts to yield mainly cyclohexanone or cyclohexanol.

  18. Characterization and photocatalytic activity of lanthanon-doped nano-TiO II

    Science.gov (United States)

    Wei, Zhang Z.; Jun, Fan; Qian, Zhang; Yun, Hu X.; Dong, Li Z.; Liang, Chen G.

    2006-02-01

    Nano-TiO II powder and TiO II optical films with photocatalytic activity were prepared by sol-gel progress. Eu 3+,Nd 3+,Tb 3+,Dy 3+ were adoped to enhance the photocatalytic activity. The modality of the films was observed with AFM morphology; Three-dimensional picture of TiO II by AFM (RMS=2.83nm) showed its fine quality. Samples annealed at different temperatures were analyzed with UV-VIS spectroscopy. The results indicated that the absorption of the sample annealed at 500 °C is strong because it is composed of anatase and rutile sized about 10~100nm (ref. XRD). XRD was used to analyze the structure of TiO II. The results showed that rutile phase is precipitated as well as anatase of TiO II,and anatase is about 66wt%,and the average dimension is 26nm; Alumina-supported vanadium oxide catalyst (V IIO 5/Al IIO 3) was prepared conventionally by impregnating alumina with an aqueous solution of ammonium metavanadate(NH 4VO 3). Cyclohexanol and cyclohexanone are key reactants for the production of adipic acid and caprolactam. The photo-oxidation of cyclohexane on titanium dioxide and over V IIO 5/Al IIO 3 was investigated in neat cyclohexane to synthesize cyclohexanone and cyclohexanol. The reaction also features the photocatalytic activity of Nano-TiO II and V IIO 5/Al IIO 3. The results indicate that titanium dioxide doped with Eu or Tb exhibits the high selectivity to partial oxidation compounds. The characteristic of the reaction over V IIO 5/Al IIO 3 is a reasonable (K/A) ketone/alcohol ratio.

  19. 磁性催化剂与磁稳定床反应器或磁集成强化反应过程%Intensification catalytic reaction by integration of magnetic catalyst and magnetically stabilized bed reactor or magnetic separator

    Institute of Scientific and Technical Information of China (English)

    宗保宁

    2012-01-01

    通过将非晶态镍合金催化剂的磁性和加氢活性与磁稳定床反应器集成,实现了在己内酰胺加氢精制过程的工业应用.磁稳定床加氢精制替代己内酰胺氧化精制过程,显著提高了反应过程的能效和物效,并减少了污染物排放.非晶态镍合金催化剂与磁分离集成,强化了苯甲酸加氢反应过程.磁性Pd/Al2O3和NiSO4/Al2O3催化剂与磁稳定床反应器集成,强化了乙炔选择性加氢反应和烯烃叠合反应,形成了新技术生长点.%Utilizing the excellent hydrogenation activity and magnetism of the amorphous Ni catalyst, a magnetically stabilized bed reactor was developed for the purification of caprolactam, to ensure higher reactor and process efficiency. Integration of amorphous Ni catalyst and magnetic separator has enhanced the benzoic acid hydrogenation reaction to reduce the Pd/C catalyst consumption by 50%, and to increase the plant output by 15%, respectively. Integration of the appropriate magnetic catalyst into the magnetically stabilized bed reactor also allowed improved performances in selective hydrogenation of acetylene and olefin oligomerization, compared with current processes, and thus constitutes a highly effective technique for process intensification.

  20. Thermoresponsive polymeric gel as an on-demand transdermal drug delivery system for pain management.

    Science.gov (United States)

    Indulekha, S; Arunkumar, P; Bahadur, D; Srivastava, R

    2016-05-01

    The main aim of this work is to design a heat triggered transdermal drug delivery system (TDDS) using a thermoresponsive polymer, poly (N-vinyl caprolactam) [PNVCL] based gel, where in patients can themselves administer a pulse of drug on mere application of heat pad over the TDDS, whenever pain is experienced. The phase transition temperature of PNVCL was tuned to 35 °C by grafting it onto a pH sensitive biopolymer, Chitosan, to synthesize Chitosan-g-PNVCL (CP) co-polymer which render the gel both thermo- and pH-responsive property. The application of triggered delivery was explored by loading acetamidophenol (a model hydrophilic drug) and etoricoxib (a model hydrophobic drug). In vitro drug release experiments were performed at three different temperatures (25, 32 and 39 °C) at two different pH (5.5 and 7) to study its drug release with response to temperature and pH. Drug release profiles obtained were found to have enhanced release for both the drugs respectively at 39 °C (above LCST) and pH5.5 when compared to other release conditions. In vitro skin permeation of both the drugs performed in rat abdominal skin using Franz diffusion cell showed enhanced drug release when the skin was subjected to higher temperature (39 °C). Moreover, it was also found that skin permeation for hydrophobic drug was better than that of hydrophilic drug. The in vivo biocompatibility studies of the CP gel in rat skin proved that the gel is biocompatible. The results obtained demonstrated the potential use of the thermoresponsive CP gel as an on-demand localized drug delivery system.

  1. Molecular dynamics simulations of methane hydrate pre-nucleation phenomena and the effect of PVCap kinetic inhibitor

    Science.gov (United States)

    Kuznetsova, Tatiana; Kvamme, Bjørn; Parmar, Archana

    2012-12-01

    MD simulations were employed to investigate a number of different systems of relevance for methane hydrate formation, dissociation and inhibition. Regions of stability for methane hydrate have been investigated using a model system consisting of a slab of hydrate embedded in liquid water. Water/methane interface structuring and possible precursors to hydrate formation have been investigated using a model system of water and methane at different densities. In yet another system we have investigated the impact of Dodecamers (twelve-unit molecules) of poly (vinyl caprolactam) or PVCap on structuring of water/methane interfaces. PVCap is well known for its performance as hydrate kinetic inhibitor1. Intermolecular interactions were treated by a combination of Coulomb and Lennard-Jones potentials. Temperature was controlled by a simple velocity scaling. Several of the hydrate-containing systems showed a tendency to melt when in contact with methane-saturated water even at temperatures well below the hydrate stability region. We have attributed this behavior to the fact that hydrate volume available in a MD experiment is small and lacks the stabilizing presence of bulk. Systems containing liquid water and methane showed certain signs of hydrate nucleation. The PVCap behavior was shown to be very dependent on its concentration in water. At low concentrations, PVCap tended to prefer the water-methane interface and not to interact with each other, similarly to another kinetic inhibitor, PVP2. When the liquid PVCap content was high, it evidently modified the interfacial tension of water-methane surface, converting the initially disperesed methane phase into separated bubbles. The PVCap molecules then built a system-wide network that partially covered the surface of methane bubbles.

  2. Reactive processing of textile-natural fiber reinforced anionic polyamide-6 composites

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Ze; Chen, Peng; Liu, Zhengying; Feng, Jianmin; Yang, Mingbo [College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, Sichuan (China)

    2015-05-22

    Nowadays natural fiber, used in reinforced composites, is widely concerned. However, no natural fiber reinforced reactive thermoplastic polymer grades had been prepared so far. Through our studies, it was demonstrated that there was a severe retardation and discoloration occurred in the reactive processing between anionic polyamide-6 (APA-6) and natural fiber, which result in incomplete polymerization when put together. In order to solve the problem, two methods were adopted in this paper, which are fiber pretreatment and usage of a new-style initiator called caprolactam magnesium bromide. The former is to remove sizing agent and impurities on the surface of fiber, and the latter is to weaken the side reactions between APA-6 and natural fiber by the nature of its lower reactivity and weaker alkaline. In cooperation with both methods, the severe retardation and discoloration had been improved significantly, so that the polymerization of APA-6 in natural fiber was occurred smoothly. Following textile-natural fiber reinforced APA-6 composites with an average thickness of 2.5 mm and a fiber volume content of 50% was prepared by vacuum assisted resin transfer molding (VARTM). The soxhlet extraction, dilute solution viscometry and differential scanning calorimeter (DSC) measurements respectively suggested the degree of conversion, viscosity-average molar mass and crystallization of composites was up to 94%, 11.3×104 and 50%. Remarkable improvement of mechanical properties were achieved through dynamic mechanical analysis (DMA), tensile and three-point bending test. Favorable interfacial adhesion and wettability were revealed by scanning electron microscopy (SEM) observation. Therefore, all of the above good performance make this new-style and environmentally friendly composites have broad application prospects.

  3. High-level conversion of L-lysine into 5-aminovalerate that can be used for nylon 6,5 synthesis.

    Science.gov (United States)

    Park, Si Jae; Oh, Young Hoon; Noh, Won; Kim, Hye Young; Shin, Jae Ho; Lee, Eun Gyo; Lee, Seungwoon; David, Yokimiko; Baylon, Mary Grace; Song, Bong Keun; Jegal, Jonggeon; Lee, Sang Yup; Lee, Seung Hwan

    2014-10-01

    L-Lysine is a potential feedstock for the production of bio-based precursors for engineering plastics. In this study, we developed a microbial process for high-level conversion of L-lysine into 5-aminovalerate (5AVA) that can be used as a monomer in nylon 6,5 synthesis. Recombinant Escherichia coli WL3110 strain expressing Pseudomonas putida delta-aminovaleramidase (DavA) and lysine 2-monooxygenase (DavB) was grown to high density in fed-batch culture and used as a whole cell catalyst. High-density E. coli WL3110 expressing DavAB, grown to an optical density at 600 nm (OD600 ) of 30, yielded 36.51 g/L 5AVA from 60 g/L L-lysine in 24 h. Doubling the cell density of E. coli WL3110 improved the conversion yield to 47.96 g/L 5AVA from 60 g/L of L-lysine in 24 h. 5AVA production was further improved by doubling the L-lysine concentration from 60 to 120 g/L. The highest 5AVA titer (90.59 g/L; molar yield 0.942) was obtained from 120 g/L L-lysine by E. coli WL3110 cells grown to OD600 of 60. Finally, nylon 6,5 was synthesized by bulk polymerization of ϵ-caprolactam and δ-valerolactam prepared from microbially synthesized 5AVA. The hybrid system demonstrated here has promising possibilities for application in the development of industrial bio-nylon production processes.

  4. [Migration of monomers and primary aromatic amines from nylon products].

    Science.gov (United States)

    Mutsuga, Motoh; Yamaguchi, Miku; Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    Migration of 2 kinds of monomer and 21 kinds of primary aromatic amines (PAAs) from 21 kinds of nylon products such as turners, ladles and wrap film were determined. Samples were classified as regards materials by mean of pyrolysis-GC/MS. One sample was classified as nylon 6, 15 samples as nylon 66 and three samples as nylon 6/66 copolymers, while two samples were laminate of nylon 6 with polyethylene or polypropylene. All of the nylon 66 samples contained a small amount of ε-caprolactam (CPL), which is the nylon 6 monomer. Migration levels of monomers and PAAs at 60°C for 30 min into 20% ethanol were measured by LC/MS/MS. CPL was detected at the level of 0.015-38 µg/mL from all samples, excluding one wrap film sample, and 1,6-hexamethylenediamine was detected at the level of 0.002-0.013 µg/mL from all nylon 66 samples and one nylon 6/66 sample. In addition, 0.006-4.3 µg/mL of 4,4'-diaminodiphenylmethane from three samples, 0.032-0.23 µg/mL of aniline from four samples, 0.001 µg/mL of 4-chloroaniline from two samples, and 0.002 µg/mL of 2-toluidine and 0.066 mg/mL of 1-naphthylamine from one sample each were detected. The migration levels at 95 or 121°C were about 3 and 10 times the 60°C levels, respectively.

  5. Investigation of the in vitro performance difference of drug-Soluplus® and drug-PEG 6000 dispersions when prepared using spray drying or lyophilization

    Directory of Open Access Journals (Sweden)

    Mohammad A. Altamimi

    2017-03-01

    Full Text Available Purpose: To evaluate the physicochemical and in vitro characteristics of solid dispersions using BCS II model drugs with Soluplus® and one of its component homopolymers, PEG 6000. Methods: Nifedipine (NIF and sulfamethoxazole (SMX of 99.3% and 99.5% purity, respectively, were selected as BCS II model drugs, such that an improved dissolution rate and concentration in the gastrointestinal tract should increase oral bioavailability. Soluplus® is an amorphous, tri-block, graft co-polymer with polyvinyl caprolactam, polyvinyl acetate, and polyethylene glycol (PCL:PVAc:PEG6000 in the ratio 57:30:13. PEG 6000 (BASF is a waxy material with melting point of about 60 °C. Solid dispersions were prepared using lyophilization or spray drying techniques. Dissolution study, crystallinity content, and analysis for new chemical bond formation have been used to evaluate the dispersed materials. Results: Although each polymer improved the drug dissolution rate, dissolution from Soluplus® was slower. Enhanced dissolution rates were observed with NIF solid dispersions, but the dissolution profiles were quite different due to the selected technique, polymer, and dissolution medium. For SMX, there was similarity across the dissolution profiles despite the medium, polymer, or applied technique. Each polymer was able to maintain an elevated drug concentration over the three hour duration of the dissolution profile, i.e., supersaturation was supported by the polymer. DSC thermograms revealed no melting endotherm, suggesting that the drug is amorphous or molecularly dispersed. Conclusion: NIF and SMX solid dispersions were successfully prepared by spray drying and lyophilization using Soluplus® or PEG 6000. Each polymer enhanced the drug dissolution rate; NIF dissolution rate was improved to a greater extent. Dispersions with PEG 6000 had a faster dissolution rate due to its hydrophilic nature. DSC analysis showed that no crystalline material exists in the

  6. Tribological Behavior of MC Nylon6 Composites Filled with Glass Fiber and Fly ash

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shihua; CUI Chong; CHEN Guang

    2012-01-01

    To improve tribological property of MC Nylon6,the glass fiber and fly ash reinforced monomer casting nylon composites (GFFAPA) were prepared by anionic polymerization of ε-caprolactam.The friction and wear behaviors of composites under dry condition,water lubrication and oil lubrication were investigated through a ring-black wear tester.Worn surfaces were analyzed using a scanning electron microscope.The experimental results show that the tensile strength and hardness of nylon composites are obviously improved with reinforcement increasing.Compared to MC nylon,the lowest friction coefficient and wear rate of glass fiber reinforced nylon composites (GFPA) with GF30% respectively decrease by 33.1% and 65.3%,of fly ash reinforced nylon composites (FAPA) with FA20% decrease by 5.2% and 68.9% and of GFFAPA composites with GF30% and FA10% decrease by 57.8% and 89.9%.The main wear mechanisms of FAPA composites are adhesive and abrasive wear and of GFPA composites with high proportion are abrasive and fatigue wear.The worn surfaces of GFFAPA composites are much multiplex and the optional distributing glass fiber and fly ash have a synergetic effect on the wear resistance for GFFAPA composites.Compared with dry friction,the friction coefficient and wear rate under oil lubricated conditions decrease sharply while the latter reversely increase under water lubricated conditions.The wear mechanisms under water lubricated condition are principally chemical corrosion wear and abrasive wear and they become boundary friction under oil lubricated condition.

  7. Molecular interaction between glimepiride and Soluplus®-PEG 4000 hybrid based solid dispersions: Characterisation and anti-diabetic studies.

    Science.gov (United States)

    Reginald-Opara, Joy Nneji; Attama, Anthony; Ofokansi, Kenneth; Umeyor, Chukwuebuka; Kenechukwu, Frankline

    2015-12-30

    The objective of this study was to evaluate a novel blend of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol 6000 grafted copolymer (Soluplus®) and polyethylene glycol (PEG) 4000 for solubility enhancement, physicochemical stability and anti-diabetic efficacy of the produced solid dispersions containing glimepiride, a biopharmaceutics classification system (BCS) class II sulphonylurea. Different batches of glimepiride solid dispersions (SD) were prepared by the solvent evaporation method using the individual polymers and blends of the polymers at different ratios. The Soluplus®-PEG 4000 (sol-PEG) hybrid polymer based glimepiride solid dispersions were characterized by differential scanning calorimetry (DSC), fourier transform infrared (FTIR) spectroscopy, micromeritics and dissolution studies. In vivo anti-diabetic activity was determined by measuring the changes in blood glucose concentrations in albino rats. The solid dispersions showed good flow properties and excellent practical yield. Drug content and release from the different formulations increased when Soluplus® was used as the main matrix polymer. The kinetics of drug release from all the solid dispersions followed first order. Solid state characterization confirmed the formation of amorphous glimepiride solid dispersions in the Sol-PEG hybrid polymer and no strong drug-polymer interaction was observed. The blood glucose reduction in albino rats by the Sol-PEG-Glim SDs was significantly (p<0.05) higher and more sustained when compared with the plain drug sample and commercially available product. Optimized SD batches (SP1 and SP3) showed a reduction in blood glucose level from 100% to 9.81% and 8.97%, respectively, at Tmax of 3h. The Sol-PEG-Glim SD was found to be stable over a period of 6 months (at 40°C, 70% RH) with no significant changes in the drug content. Thus, the Sol-PEG polymeric hybrids represent a promising tool for enhanced delivery of glimepiride.

  8. Construction of drug-polymer thermodynamic phase diagrams using Flory-Huggins interaction theory: identifying the relevance of temperature and drug weight fraction to phase separation within solid dispersions.

    Science.gov (United States)

    Tian, Yiwei; Booth, Jonathan; Meehan, Elizabeth; Jones, David S; Li, Shu; Andrews, Gavin P

    2013-01-07

    Amorphous drug-polymer solid dispersions have the potential to enhance the dissolution performance and thus bioavailability of BCS class II drug compounds. The principle drawback of this approach is the limited physical stability of amorphous drug within the dispersion. Accurate determination of the solubility and miscibility of drug in the polymer matrix is the key to the successful design and development of such systems. In this paper, we propose a novel method, based on Flory-Huggins theory, to predict and compare the solubility and miscibility of drug in polymeric systems. The systems chosen for this study are (1) hydroxypropyl methylcellulose acetate succinate HF grade (HPMCAS-HF)-felodipine (FD) and (2) Soluplus (a graft copolymer of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol)-FD. Samples containing different drug compositions were mixed, ball milled, and then analyzed by differential scanning calorimetry (DSC). The value of the drug-polymer interaction parameter χ was calculated from the crystalline drug melting depression data and extrapolated to lower temperatures. The interaction parameter χ was also calculated at 25 °C for both systems using the van Krevelen solubility parameter method. The rank order of interaction parameters of the two systems obtained at this temperature was comparable. Diagrams of drug-polymer temperature-composition and free energy of mixing (ΔG(mix)) were constructed for both systems. The maximum crystalline drug solubility and amorphous drug miscibility may be predicted based on the phase diagrams. Hyper-DSC was used to assess the validity of constructed phase diagrams by annealing solid dispersions at specific drug loadings. Three different samples for each polymer were selected to represent different regions within the phase diagram.

  9. 一种新型TPE的合成与表征%Synthesis and characterization of a new type of thermoplastic elastomer

    Institute of Scientific and Technical Information of China (English)

    李羿; 彭治汉

    2011-01-01

    采用己内酰胺、4,4'-二苯基甲烷二异氰酸酯(MDI)、四氢呋喃聚醚(PTMC)和己二酸合成聚酰胺(PA)6-MDI/PTMG热甥性弹性体.通过红外光谱、差示扫描量热法、热重分析等表征聚合物的化学结构和物理性能.随着软段PTMG含量的增加,聚合物的硬度、拉伸强度下降,拉伸断裂应变和韧性提高.从扫描电子显微镜照片中发现,PA 6-MDI/PTMG弹性体没有明显的相分离.%Polyamide (PA) 6-4,4'-diphenylmethane diisocyanate (MDI)/Poly (tetramethylene glycol)(PTMG)thermoplastic elastomer were synthesized by three-step melt polymerization from ε-caprolactam, MDI, PTMG and adipic acid. The chemical structure and physical properties of the polymers were characterized by means of infrared spectroscopy(IR), differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA), etc.The rigidity and tensile strength of PA 6-MDI/PTMG decreased as the content of PTMG soft segment augmented, while the tensile strain at break and flexibility increased. No obvious phase separation occurred in PA 6-MDI/PTMG elastomer as revealed by the observation of scanning electron microscope(SEM).

  10. Preparation of carbamazepine-Soluplus solid dispersions by hot-melt extrusion, and prediction of drug-polymer miscibility by thermodynamic model fitting.

    Science.gov (United States)

    Djuris, Jelena; Nikolakakis, Ioannis; Ibric, Svetlana; Djuric, Zorica; Kachrimanis, Kyriakos

    2013-05-01

    Hot-melt extrusion (HME) is a dust- and solvent-free continuous process enabling the preparation of a variety of solid dosage forms containing solid dispersions of poorly soluble drugs into thermoplastic polymers. Miscibility of drug and polymer is a prerequisite for stable solid dispersion formation. The present study investigates the feasibility of forming solid dispersions of carbamazepine (CBZ) into polyethyleneglycol-polyvinyl caprolactam-polyvinyl acetate grafted copolymer (Soluplus) by hot-melt extrusion. Physicochemical properties of the raw materials, extrudates, co-melted products, and corresponding physical mixtures were characterized by thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), attenuated total reflectance infrared (ATR-FTIR) spectroscopy and hot stage microscopy (HSM), while miscibility of CBZ and Soluplus was estimated on the basis of the Flory-Huggins theory, Hansen solubility parameters, and solid-liquid equilibrium equation. It was found that hot-melt extrusion of carbamazepine and Soluplus is feasible on a single-screw hot-melt extruder without the addition of plasticizers. DSC analysis and FTIR spectroscopy revealed that a molecular dispersion is formed when the content of CBZ does not exceed ∼5% w/w while higher CBZ content results in a microcrystalline dispersion of CBZ form III crystals, with the molecularly dispersed percentage increasing with extrusion temperature, at the risk of inducing transformation to the undesirable form I of CBZ. Thermodynamic modeling elucidated potential limitations and temperature dependence of solubility/dispersibility of carbamazepine in Soluplus hot-melt extrudates. The results obtained by thermodynamic models are in agreement with the findings of the HME processing, encouraging therefore their further application in the HME process development.

  11. Synthesis and Characterization of Star-Shaped Nylon 6 with Four Arms%四臂星型尼龙6的合成与表征

    Institute of Scientific and Technical Information of China (English)

    付鹏; 井琼琼; 刘民英; 杨韶辉; 王玉东; 赵清香

    2011-01-01

    Four kinds of star-shaped nylon 6 samples with different branched-chain length were prepared by the hydrolytic polymerization of ε-caprolactam using 2,2,6,6-tetra(β-carboxyethyl)cyclohexanone as tetrafunctional reactant.The molecular weight of prepared star-shaped nylon 6 was determined by end group titration, and mechanical properties and rheological behavior were also investigated.Compared with linear chain nylon 6 with similar molecular weight,the tensile and bending strength of star-shaped nylon 6 can be maintained,impact strength retention over 75%,elongation at break decreases by 15% maximally,relative viscosity reduces 25%,melting index increases nearly 4 times,balance torque reduces 75%.The prepared star-shaped nylon 6 presents good flow ability.%以2,2,6,6-四丙酸环己酮为四官能团核心,进行己内酰胺的水解开环聚合,合成了四种不同臂长的四臂星型尼龙6,对产物的分子量进行了测定,并对其力学性能和流变行为进行了研究。结果表明,四臂星型尼龙6的分子量随着四丙酸环己酮含量的提高而降低,与相应分子量的线型尼龙6相比,星型尼龙6的拉伸强度和弯曲强度基本保持,冲击强度保持率在75%以上,断裂伸长率最大降低了15%,相对黏度降低了近25%,熔融指数提高了近4倍,平衡转矩降低了75%,表现出了较好的加工流动性。

  12. 纳米SiO_2表面处理对MC尼龙复合材料结构与性能的影响%Effects of pretreated nano-silica on the structure and properties of MC nylon composites

    Institute of Scientific and Technical Information of China (English)

    张士华; 崔崇; 陈光

    2011-01-01

    为提高MC尼龙的综合性能,采用KH-550硅烷偶联剂处理纳米SiO2,根据阴离子聚合反应制备MC尼龙SiO2纳米复合材料,探讨了表面处理纳米SiO2与熔体的作用机理,并进行复合材料的结构表征与性能测试.研究表明:纳米SiO2表面包覆硅烷偶联剂,其有机官能团氨基进攻聚合反应体系中酰亚胺结构的羰基,两者通过化学键实现界面结合;纳米SiO2粒子均匀分散在尼龙基体中,对尼龙6的结晶过程起到异相成核作用;当复合材料受到外力时,纳米粒子通过界面作用带动基体产生屈服耗散能量,阻碍裂纹扩展,实现增强增韧作用;纳米SiO2质量分数为1%时复合材料的力学性能最优.%To improve the comprehensive properties of MC nylon,nano-silica particles were pretreated with silane coupling agents KH-550,and silica reinforced monomer casting nylon composites were successfully prepared by anionic polymerization of ε-caprolactam.The structure and properties of MC nylon composites were investigated in detail.The results showed that lots of macromolecule chains with imide group were produced after sodium hydroxide was added into polymerization reaction system.The amido of silane coupling agent grafted on nana-silica particles could attack carbonyl group of imido group during polymerization reaction so that strong chemical bonds combined nano-silica and nylon matrix.The nano-silica particles were dispersed uniformly in nylon matrix.They played the role of heterogeneous nucleating agents,improved the crystallization rate of matrix,served as chemical cross-link points in the composite,droved matrix yield through interfacial interaction thus blocking tiny crack spreading and absorbed more energy.The optimum comprehensive mechanical properties could be achieved in case of the composite containing 1wt% silica.

  13. Preparation and Characterization of Biomimetic Hydroxyapatite-Resorbable Polymer Composites for Hard Tissue Repair

    Science.gov (United States)

    Hiebner, Kristopher Robert

    Autografts are the orthopedic "gold standard" for repairing bone voids. Autografts are osteoconductive and do not elicit an immune response, but they are in short supply and require a second surgery to harvest the bone graft. Allografts are currently the most common materials used for the repair of segmental defects in hard tissue. Unlike autografts, allografts can cause an undesirable immune response and the possibility of disease transmission is a major concern. As an alternative to the above approaches, recent research efforts have focused on the use of composite materials made from hydroxyapatite (HA) and bioresorbable polymers, such as poly-L-lactide (PLLA). Recent results have shown that the surface hydroxides on HA can initiate the ring opening polymerization (ROP) of L-lactide and other lactones creating a composite with superior interfacial strength. This thesis demonstrates that the surface of porous biologically derived HA substrates, such as coralline HA and trabecular bone, can be used to initiate the ROP of L-lactide and other lactones from the vapor phase. This process increases the strength of the porous scaffold through the deposition of a thin, uniform polymer coating, while maintaining the porous structure. The kinetics of the chemical vapor deposition polymerization (CVDP) are described using a quartz crystal microbalance (QCM). The reaction temperature and monomer vapor pressure are found to affect the rate of the polymerization. Also described in this thesis is the preparation of a porous polymer scaffold that mimics the structure of demineralized bone matrix (DBM). This demineralized bone matrix simulant (DBMS) is created using anorganic bovine bone as a template to initiate the polymerization of various lactones, followed by the removal of the HA scaffold. This material retained its shape and exhibits mechanical properties superior to DBM. Finally it is shown that HA can be used to initiate the ROP of a-caprolactam and the biocompatibility

  14. Effect of the acidic strength on the vapor phase Beckmann rearrangement of cyclohexanone oxime over the MFI zeolite: an embedded ONIOM study.

    Science.gov (United States)

    Sirijaraensre, Jakkapan; Limtrakul, Jumras

    2009-01-21

    The mechanism and energetic profile of the Beckmann rearrangement reaction of cyclohexanone oxime to epsilon-caprolactam catalyzed by the H-[Al]-MFI and H-[B]-MFI zeolites were investigated by both the bare cluster and the ONIOM models at the B3LYP/6-31G(d,p) and the B3LYP/6-31G(d,p):MNDO levels of theory, respectively. In order to improve the energetic properties and take into account the whole zeolite framework effect, single point calculations are undertaken at the embedded ONIOM2 schemes; MP2/6-311G(d,p):HF/6-31G(d) with an additional long-range electrostatic potential from the extended zeolite framework. The reaction mechanism of the Beckmann rearrangement over the acid site of zeolites consists of three steps: the 1,2 H shift, the rearrangement and the tautomerization. The activation energies for the Beckmann rearrangement of cyclohexanone oxime on the H-[Al]-MFI zeolite are calculated to be 31.46, 16.15 and 18.95 kcal mol(-1), for the first, second and third steps, respectively, whereas in the H-[B]-MFI zeolite, the energy barriers for each step of the reaction are 24.33, 7.46 and 20.43 kcal mol(-1), respectively. The rate-determining step of the reaction is the first step, which is the transformation from the N-ended cyclohexanone oxime adsorption complex and the O-ended one. These results signify the important role that the acid strength of zeolites plays in altering the energy profile of the reaction. The results further indicate that the weak Brønsted acid sites in the [B]-MFI zeolite could better catalyze the Beckmann rearrangement of cyclohexanone oxime than the strong acid sites in the [Al]-MFI zeolite, as compared with the quantitatively low activation energy of most steps. However, the turnover reaction of the H-[B]-MFI zeolite might be delayed by the quantitatively high desorption energy of the product as compared to the adsorption energy of the reactant.

  15. Estudos sobre a toxicologia da ε-caprolactama

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Justo Bomfim

    2009-03-01

    Full Text Available A ε-caprolactama (CAP é um monômero precursor de polímeros denominados nylon 6. Esses polímeros destinam-se à produção de tapetes, vestuário e materiais plásticos tais como equipamentos, sistemas e componentes automotivos, conectores, além de embalagens plásticas. Resíduos de CAP podem migrar de embalagens plásticas de nylon 6 para os alimentos. Diante disso, foi de interesse realizar uma revisão dos efeitos relativos à exposição à CAP e o seu impacto sobre a saúde humana. Estudos epidemiológicos indicam a possibilidade da CAP causar inflamações oculares e cutâneas, além de irritações no sistema respiratório. Pode ocorrer ainda hipotensão, taquicardia, palpitações, rinorréia, ressecamento nasal, efeitos geniturinários e sobre a reprodução como distúrbios nas funções menstrual e ovariana, e complicações no parto; além de problemas neurológicos e hematológicos. Estudos com animais são consistentes com tais relatos. Os estudos de genotoxicidade in vitro e in vivo por via oral e intraperitoneal mostram em sua grande maioria, resultados negativos, bem como ausência de efeitos carcinogênicos em ratos e camundongos e sobre o desenvolvimento e reprodução em ratos e coelhos.ε -Caprolactam (CAP is a precursor monomer of nylon 6 polymers. Nylon 6 is used in the manufacture of carpets, clothes and plastic materials, such as equipment, systems and automotive components, connectors and plastic packaging. CAP residues can migrate from nylon 6 plastic packaging to foods. Given this fact, this review was realized concerning the effects of CAP exposure and its impact on human health. Epidemiological studies indicate that CAP could cause ocular, cutaneous and respiratory irritations, as well as hypotension, tachycardia, palpitations, rhinorrhea, nose dryness, neurological and blood problems, and genitourinary and reproductive effects, such as alterations in ovarian-menstrual functions and pregnancy

  16. Non-targeted plasma metabolome of early and late lactation gilts

    Directory of Open Access Journals (Sweden)

    Lea A Rempel

    2016-11-01

    Full Text Available Female pigs nursing their first litter (first-parity gilts have increased energy requirements not only to support their piglets, but they themselves are still maturing. Non-targeted plasma metabolomics were used to investigate the differences between 1 post-farrowing and weaning (early or late lactation, 2 degree of body condition loss after lactation (extreme or minimal, and 3 interactions; to potentially identify compounds or pathways that could aide in alleviating energetic demands of lactation in gilts. Twenty first-parity gilts were selected with similar (P ≥ 0.4475 number of piglets born and nursed, and similar (P ≥ 0.3141 body condition traits (e.g. body weight and backfat thickness post-farrowing, yet exhibited minimal or extreme loss (P ≤ 0.0094 in body weight (8.6 ± 1.48 kg and 26.1 ± 1.90 kg, respectively and backfat thickness (1.3 ± 0.67 mm and 4.7 ± 0.86 mm, respectively following lactation (weaning. Plasma samples from first-parity gilts at post-farrowing and weaning were investigated using UPLC-MS and GC-MS to generate a comprehensive metabolic profile. Each approach yielded approximately 700 detected compounds. An ANOVA was performed on each detected compound in R for time of collection, body condition change, and the interaction, followed by a false discovery correction. Two unknown compounds were different (P ≤ 0.05 for extreme versus minimal body condition change. Several compound differences (P ≤ 0.05 were identified between post-farrowing and weaning. Thirty-two compounds detected by UPLC-MS had at least a log2 fold-change of ±1.0 while only 18 compounds had a log2 fold-change of ±0.6 for the significant GC-MS compounds. Annotation implicated various metabolic pathways. Creatinine was greater at weaning (P = 0.0224 and others have reported increased serum concentrations of creatinine in response to body weight loss. Hippurate and caprolactam, associated with protein catabolism, were also greater (P ≤ 0

  17. Evaluation of Hydrate Inhibition Performance of Water-soluble Polymers using Torque Measurement and Differential Scanning Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kyuchul; Park, Juwoon; Kim, Jakyung; Kim, Hyunho; Seo, Yutaek [KAIST, Daejeon (Korea, Republic of); Lee, Yohan; Seo, Yongwon [UNIST, Ulsan (Korea, Republic of)

    2014-12-15

    In this work, hydrate inhibition performance of water-soluble polymers including pyrrolidone, caprolactam, acrylamide types were evaluated using torque measurement and high pressure differential scanning calorimeter (HP µ-DSC). The obtained experimental results suggest that the studied polymers represent the kinetic hydrate inhibition (KHI) performance. 0.5 wt% polyvinylcaprolactam (PVCap) solution shows the hydrate onset time of 34.4 min and subcooling temperature of 15.9 K, which is better KHI performance than that of pure water - hydrate onset time of 12.3 min and subcooling temperature of 6.0 K. 0.5 wt% polyvinylpyrrolidone (PVP) solution shows the hydrate onset time of 27.6 min and the subcooling temperature of 13.2 K while polyacrylamide-co-acrylic acid partial sodium salt (PAM-co-AA) solution shows less KHI performance than PVP solution at both 0.5 and 5.0 wt%. However, PAM-co-AA solution shows slow growth rate and low hydrate amount than PVCap. In addition to hydrate onset and growth condition, torque change with time was investigated as one of KHI evaluation methods. 0.5 wt% PVCap solution shows the lowest average torque of 6.4 N cm and 0.5 wt% PAM-co-AA solution shows the average torque of 7.2 N cm. For 0.5 wt% PVP solution, it increases 11.5 N cm and 5.0 wt% PAM-co-AA solution shows the maximum average torque of 13.4 N cm, which is similar to the average torque of pure water, 15.2 N cm. Judging from the experimental results obtained by both an autoclave and a HP µ-DSC, the PVCap solution shows the best performance among the KHIs in terms of delaying hydrate nucleation. From these results, it can be concluded that the torque change with time is useful to identify the flow ability of tested solution, and the further research on the inhibition of hydrate formation can be approached in various aspects using a HP µ-DSC.

  18. Silicalite-1空心球材料制备及其在Beckmann重排反应中催化应用研究%Synthesis of Silicalite-1 hollow sphere catalyst and its application for Beckmann rearrangement reaction

    Institute of Scientific and Technical Information of China (English)

    金亚美; 董梅; 王国富; 王浩; 李俊汾; 樊卫斌; 王建国; 秦张峰

    2016-01-01

    以碳微球作为硬模板、纳米 Silicalite-1分子筛作为壳层,采用水热法合成了 Silicalite-1空心球材料。采用 XRD、SEM、FT-IR、N2吸附、29 Si MAS NMR、TG、XPS等技术对催化剂的物相、形貌和性能等进行表征,发现该空心材料具有较高的结晶度、发达的多级孔道结构和丰富的表面羟基。与传统方法制备的Silicalite-1分子筛催化剂相比,Silicalite-1空心材料在环己酮肟Beckmann重排反应中表现出优异的催化性能,使环己酮肟的转化率达99%、己内酰胺的选择性达94%,同时催化剂保持极佳的稳定性。研究表明,Silicalite-1空心材料中具有的大量巢式硅羟基和末端硅羟基是Beckmann重排反应的主要活性位,且可通过简单焙烧再生实现羟基活性位的完全恢复。%Silicalite-1 zeolite hollow sphere structured material was hydrothermally synthesized via the aid of carbon microspheres as hard-template. The morphology, structure, textural and physicochemical properties of the material were characterized with XRD, SEM, FT-IR, N2 adsorption-desorption isotherm, 29 Si MAS NMR, TG, and XPS techniques. It was suggested that the obtained Silicalite-1 hollow spheres were highly crystallized with developed multiple channel structure and abundant surface hydroxyl groups, which endowed the material with excellent catalytic properties in Beckmann rearrangement reaction of cyclohexanone-oxime. Compared with the Silicalite-1 catalyst prepared from conventional method, the Silicalite-1 hollow sphere catalyst showed much higher activity to the conversion of cyclohexanone-oxime ( 99%) and selectivity of caprolactam ( 94%) , with excellent stability at the same time. The abundant nest silanols and terminal silanols in Silicalite-1 hollow sphere were main active sites for Beckmann rearrangement reaction, and could be easily recovered from the deactivated catalysts by calcination.

  19. 阳离子结构对磺酸基离子液体酸强度的影响规律%Influence Rule of Cationic Structure on Acid Strength of Sulfonic Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    王睿; 罗辉; 范维玉; 薛凯; 南国枝

    2015-01-01

    Eight SO3 H‐functional Brønsted acidic ionic liquids(ILs) with different nitrogen function groups were prepared and their acid strengths were investigated by UV‐Hammett combined method with p‐nitroaniline as indicator .The results demonstrated that the acid strength of the ILs increased with the increase of their concentration , while their acidity order was irrelevant to the concentration .The acidity descend of the eight acidic ILs with different nitrogen groups was in the order of the IL with caprolactam group ,pyridine group ,N‐methyl imidazole group ,trimethylamine group ,respectively .For the ILs with same nitrogen functional group ,their acid strength increased with the alkyl chain being longer . Compared with the effect of alkyl chain length on the acid strength of IL , the effect of nitrogen functional group type was more obvious . In methanol , N‐(4‐sulfonic group) butyl‐hydrogen sulfate imidazole , N‐(4‐sulfonic group ) butyl‐caprolactam hydrogen sulfate , N‐(4‐sulfonic group ) butyl‐pyridine hydrogen sulfate , N‐(3‐sulfonic group ) propyl‐pyridine hydrogen sulfate , N‐(4‐sulfonic group ) butyl‐hydrogen sulfate imidazole and N‐(3‐sulfonic group) propyl‐hydrogen sulfate imidazole showed the character of super acid , however ,in water only the first five showed the character of super acid .%采用UV‐Hammett指示剂联用法,以对硝基苯胺为指示剂,考察了阴离子为硫酸氢根,阳离子分别为三乙胺、 N‐甲基咪唑、吡啶或己内酰胺上带有丙烷基磺酸或丁烷基磺酸的8种磺酸基功能化离子液体的酸强度。结果表明,同一种离子液体的浓度越大,其酸强度越大,但不同离子液体间的相对酸强度大小顺序与离子液体的浓度无关;含氮母体化合物不同的磺酸基离子液体按酸强度由大到小排列的顺序为己内酰胺类、吡啶类、咪唑类、三乙胺类,当含氮母体化合物相同时,

  20. NTP Toxicity Studies of Cyclohexanone Oxime Administered by Drinking Water to B6C3F1 Mice (CAS No. 100-64-1).

    Science.gov (United States)

    1996-04-01

    Cyclohexanone oxime is used primarily as a captive intermediate in the synthesis of caprolactam for the production of polycaprolactam (Nylon-6) fibers and plastics and also in a variety of industrial applications. Cyclohexanone oxime was selected for study because of the potential for human exposure and the interest in oximes as a chemical class. Toxicity studies of cyclohexanone oxime (approximately 99% pure) were carried out in male and female B6C3F1 mice; the compound was administered in drinking water for 2 weeks or 13 weeks. In addition, the genetic toxicity of cyclohexanone oxime was evaluated by determining mutagenicity in Salmonella typhimurium and induction of chromosomal aberrations in cultured Chinese hamster ovary cells in vitro, with and without S9 activation. The frequency of micronucleated normochromatic erythrocytes in the bone marrow and peripheral blood of mice from the 13-week study was also determined. In the 2-week study, groups of five male and five female mice were given drinking water containing 0, 106, 312, 625, 1,250, or 2,500 ppm cyclohexanone oxime. No deaths occurred, and there was no decrease in weight gain in any group. No gross lesions were observed; there were significant increases in relative spleen weights of males and females in the 2,500 ppm group and increases in the relative liver weight of male mice exposed to 312 ppm or greater. In the 13-week studies, groups of 10 male and 10 female mice were given drinking water containing 625, 1,250, 2,500, 5,000 or 10,000 ppm cyclohexanone oxime. Deaths occurred in the 10,000 ppm groups and weight gain was depressed in males and females given 10,000 ppm and in females given 5,000 ppm. There were significant increases in relative spleen weight at exposure levels of 5,000 and 10,000 ppm and significant increases in the relative liver weights of males and females that received 10,000 ppm. Microscopically, hematopoietic cell proliferation was observed in the spleen of males and females in

  1. 钛硅分子筛的改性对环己烷氧化反应的影响%Effect of titanium silicalite modification on cyclohexane oxidation

    Institute of Scientific and Technical Information of China (English)

    宋厚杰; 齐骏鑫; 郭舒隽; 方嘉辉; 陈晓晖; 黄清明

    2016-01-01

    Hollow titanium silicalite( HTS ) was modified by different solutions of H2 SO4-H2 O2 , ( NH4 )2 CO3-H2 O2 ,( NH4 )HF2-H2 O2 and( NH4 )2 CO3 ﹢( NH4 )HF2-H2 O2 . The modified HTS samples were characterized by XRD,UV-Vis and Raman. The catalytic performance of HTS before and after modi-fication for cyclohexane selective oxidation were investigated. The results showed that the modification of HTS did not destroy its topological structure of MFI,improved the relative crystallinity of HTS,and partial anatase TiO2 was removed. Compared with the HTS,the selectivity to cyclohexanol and cyclohexanone, and the utilization rate of H2 O2 over modified HTS were improved obviously. HTS modified by the solution of( NH4 )2 CO3 ﹢( NH4 )HF2 -H2 O2 for cyclohexane selective oxidation exhibited optimal catalytic per-formance,and the selectivity to cyclohexanol and cyclohexanone was increased by 12. 78 percentage point,the utilization rate of H2 O2 was improved by 17. 33 percentage point;HTS modified by the solution of( NH4 )2 CO3 ﹢( NH4 )HF2-H2 O2 remarkably decreased H2 O2 dosage,which had good application pros-pect in the process of caprolactam production.%使用不同改性液H2 SO4-H2 O2、( NH4)2 CO3-H2 O2、( NH4)HF2-H2 O2和( NH4)2 CO3﹢( NH4)HF2-H2 O2混合溶液对中空钛硅分子筛进行改性。采用XRD、UV-Vis和拉曼光谱进行表征分析,考察改性前后钛硅分子筛在环己烷氧化反应的催化性能。结果表明,改性过程没有破坏钛硅分子筛的MFI拓扑结构,但提高了钛硅分子筛相对结晶度,并脱除了部分锐钛矿相TiO2;与未改性钛硅分子筛相比,环己醇和环己酮选择性及H2 O2有效利用率明显提高,以改性液( NH4)2 CO3﹢(NH4)HF2-H2O2改性钛硅分子筛效果最佳,醇酮选择性提高12.78个百分点,H2O2有效利用率提高17.33个百分点;( NH4)2 CO3﹢( NH4)HF2-H2 O2混合溶液改性钛硅分子筛显著降低H2 O2用量,在己内

  2. 微管内环己烷无催化氧化工艺条件对产物分布影响研究%Effects of Process Conditions on Products Distribution of Cyclohexane Non-Catalytic Oxidation in Microcapillary

    Institute of Scientific and Technical Information of China (English)

    刘懿; 朱明乔; 王磊; 陈新志; 卢建刚

    2016-01-01

    环己醇、环己酮是生产己内酰胺的原料,环己烷通过氧化反应制备上述原料的反应过程在安全性和时空收率等方面仍有挑战。今利用微通道的优异的安全和传热传质性能,采用氧气作为氧化剂,考察内径1 mm,长度5 m的不锈钢微管内环己烷无催化氧化反应的性能,重点考察了不同工艺条件,包括反应温度、反应压力、气液摩尔比和反应停留时间对环己烷氧化性能的影响。在180℃,压力1.5 MPa,氧气与环己烷的摩尔比为0.3:1,停留时间为1.5 min时,环己烷的转化率为3.93%,环己醇的选择性为23.39%,环己酮的选择性为35.95%,己二酸的选择性为26.71%,环己基过氧化氢选择性为4.78%。实验表明,微管内环己烷无催化氧化是可行的,且有一定的效果,尤其是反应时间短且安全性高,为慢反应在微管内的反应提供了借鉴。%Cyclohexanone and cyclohexanol are important raw materials for caprolactam production, and their production from non-catalytic oxidation of cyclohexane still has problems in safety and time space yield. In this paper, non-catalytic oxidation of cyclohexane was investigated in a microcapillary reactor which was made by a stainless steel tube with diameter of 1 mm and length of 5 m. Such tubes have good safety records and excellent mass and heat transfer properties. Effects of temperature, pressure, gas-liquid molar ratio and residence time on catalytic performance were studied. When the reaction is couducted under conditions of temperature 180℃, pressure 1.5 MPa, gas-liquid molar ratio 0.3 and residence time 1.5 min, the results show that the conversion of the non-catalytic cyclohexane oxidation is 3.93%, and the selectivities of cyclohexanol, cyclohexanone, adipic acid and CHHP are 23.39%, 35.95%, 26.71% and 4.78%, respectively. This study indicates that cyclohexane non-catalytic oxidation in microcapillary tubes to produce KA oil is

  3. Simulation and Control of Nylon-6 Continuous Polymerization Process%尼龙6连续聚合过程的流程模拟与调控

    Institute of Scientific and Technical Information of China (English)

    赵玲; 邢玉林; 秦春曦; 奚桢浩

    2014-01-01

    基于流程模拟软件Aspen Polymer Plus建立了己内酰胺水解聚合生产尼龙6的两段式工艺过程模型,利用该模型对某厂2万吨/年两段式生产工艺进行模拟,各聚合阶段内己内酰胺、环状二聚体含量、聚合物分子量,以及各聚合阶段温度分布和两聚合塔塔顶出水量等结果均与工业值吻合良好,模型可靠。在此基础上,进一步模拟考察了聚合反应过程中进料水含量、分子量调节剂含量、各聚合阶段温度和各聚合塔压力等因素对己内酰胺转化率、环状二聚体生成以及聚合产品分子量的影响,并进行了参数灵敏性分析。结果表明:较低的进料水含量、降低反应温度和前聚塔压力及提高后聚塔的真空度均有利于降低聚合产品中环状二聚体的含量;两个聚合塔下半段的温度变化对环状二聚体产生有显著影响,提高后聚塔真空度可显著提高聚合物分子量。以尼龙6连续聚合过程的环状二聚体含量调控为目标,在优化的操作条件下,尼龙6聚合物中环状二聚体的含量可降低约16%。%Abstrct:A model of two-steps Nylon-6 polymerization process was set up by Aspen Polymer Plus. As the simulational results fit all of the industrial operational data of 20 kt/a manufacture process well, including the composition of caprolactam and cyclic dimer, polymer molecular weight, temperature distribution, and the water yield from the top of two VK tubes, which indicated that the model was reliable. A sensitivity was analyzed by the model to evaluate the adjust ability of operational parameters, including the water and acetic acid contents in feed, temperature distribution and pressure of each VK tube in polymerization process. The results showed that low water content in feed, low reaction temperature, low pressure of the first tube and high vacuum of the secend tube contributed to less cyclic dimer fraction in polymer product. The

  4. 5种绿篱植物挥发性有机化合物成分分析%Volatile organic compounds of five hedgerow plants in Hangzhou

    Institute of Scientific and Technical Information of China (English)

    马楠; 周帅; 林富平; 高岩; 张汝民

    2012-01-01

    To explore differences in volatile organic compounds (VOCs) from different plants, VOCs from Ligus-trum quihoui var. Aureaphylla, Loropetalum chinense var. Rubrum, Buxus sinica, Ilex crenata 'Convexa', and Ilex cornuta var. Fortunei were collected using the dynamic headspace air-circulation method. The main VOCs were identified with thermal-desorption cold trap-gas chromatography-mass spectrum (TCT-GC-MS). Results showed the following major VOCs: 3-hexen-1-ol, acetate (16.30%), benzaldehyde (8.30%), nonanal (5.50%), and p-methylstyrene (5.10%) in Ligustrum quihoui; 3-hexen-1-ol, acetate (26.10%), α-pinene (6.70%), and benzaldehyde (6.50%) in Loropetalum chinense; 3-hexen-1-ol, acetate (27.10%), linalool (19.70%), and 2-octene (7.20%) in B, sinica; decanal (21.60%), nonanal (13.60%), caprolactam (6.80%), and ben zaldehyde (5.60%) in I. Crenata; and β-pinene (12.10%), decanal (9.50%), 2-nonen-1-ol (7.40%), myrcene (7.20%), limonene (6.50%), 2-octene (6.10%), and 6-methyl-5-heptene-2-one (6.1%) in I. Cornuta. These results could provide a reference for distribution of hedges.%为了探讨不同植物释放挥发性有机物(VOCs)组分和含量的差异,采用动态顶空采集法和热脱附-气相色谱-质谱(TDS-GC-MS)联用技术,分析了近自然状态下杭州地区常用绿篱植物金叶女贞Ligustrum quihoui var.aureaphylla,红花檵木Loropetalum chinese var.rubrum,瓜子黄杨Buxus sinica,龟甲冬青Ilex crenata‘Convexa’和无刺枸骨lles cornuta var.fortunei释放VOCs的种类和相对含量.结果表明:瓜子黄杨释放的VOCs主要有乙酸-3-己烯酯(相对含量为27.10%),芳樟醇(19.70%),2-辛烯(7.20%);红花檵木释放的挥发性物质主要有乙酸-3-己烯酯(26.10%),α-蒎烯(6.70%),苯甲醛(6.50%);金叶女贞主要有乙酸-3-己烯酯(16.30%),苯甲醛(8.30%),壬醛(5.50%)和对甲基苯乙烯(5.10%);无刺枸骨主要有β-蒎烯(12.10%),癸醛(9.50%),2-壬烯醇(7.40%),月桂烯(7.20

  5. Poly stock project: development and studies on new Type IV tanks for hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Barral, K.; Hembert, C.; Gerard, J. F.; Mazabraud, P.

    2005-07-01

    process consists in making the liner directly from the polyamide monomer : caprolactame in the rotomolding mold. This reaction takes place at moderate temperature. Metallic boss integration was slightly modified. Liner specific mechanical and permeation performances can be achieved by adjusting the initial chemical amount of monomer, activator and catalyst (formulation work). In parallel, 350 bar polymeric liner fully wrapped composite tank were manufactured and mechanically qualified in order to validate the composite design. Results of burst pressure and cycling are presented. The type IV tank prototype was very good at cycling : more than 55 000 cycles were reached without failure of the tank. Weight performance of the 22 liter tank, calculated as being the percentage of the mass of H2 stored on the mass of the tank filled with H2, is 4.25%. The H2 permeation rate through the liner was determined from tanks filled at very high pressure (350 bar). It was compared to laboratory measurements on disc-shaped polymer samples conducted at moderate pressure (4 to 100 bar). The material behaviour with pressure is not linear as it could have been expected. The complete study on polymer liner behaviour highlights the fact that depending on material type, permeation can be lower at high pressure. (Author)

  6. SBA-15固载酸性离子液体催化酯化反应性能%Synthesis and performance of heterogeneous catalyst of immobilized acidic ionic liquid on SBA-15 for esterification

    Institute of Scientific and Technical Information of China (English)

    胡晶晶; 赵地顺; 胡甜甜; 李静静; 翟建华

    2016-01-01

    为了减少离子液体用量及解决催化剂分离问题,采用键合法制备了以SBA-15为载体的固载化离子液体催化剂[C3SO3HCP]HSO4/SBA-15,通过FT-IR、TG、XRD、BET和TEM分析了催化剂的结构和稳定性.并将其应用于催化丁二酸酐和乙醇的酯化反应.结果表明:[C3SO3HCP]HSO4被成功固定在SBA-15上,且具有较高的热稳定性和催化活性,克服了非均相催化剂活性不高与均相催化剂难以分离的不足.在催化剂用量为反应物总质量的5%、n(C4H4O3):n(C2H5OH)=1:3,反应温度80℃;反应时间4 h、带水剂用量为反应物总质量的30%的条件下,酯收率达93.7%,且该催化剂循环使用8次后,仍具有较高的催化活性.此外,还考察了以[C3SO3HCP]HSO4/SBA-15为催化剂催化合成系列酯也获得了较高的酯收率,且易于与产物酯分离.%To decrease the usage of ionic liquid and facilitate the separation of catalyst from the product, a novel Br?nsted acidic ionic liquid catalyst of 1-(3-sulfopropyl)caprolactam hydrogen sulfate ([C3SO3HCP]HSO4) supported on SBA-15 was prepared through covalent bond grafting method. In order to achieve structural information and stability of catalysts, the samples were characterized by FT-IR, TG, XRD, BET and TEM techniques. The catalytic activities of the immobilized ionic liquid for the esterification of succinic anhydride with ethanol were investigated. It showed that [C3SO3HCP]HSO4has been successfully immobilized onto the SBA-15 with relatively good thermal stability and catalytic activity, which overcomes the drawbacks of low activity of heterogeneous catalyst, and difficult separation of homogeneous catalyst from the reaction system. Under the optimized conditions of 5%(mass) of catalyst dosage,n(C4H4O3):n(C2H5OH)=1:3, 80℃ of reaction temperature, 4 h of reaction time, and 30%(mass) of water carrying agent dosage, the yield of diethyl succinate was up to 93.7%. The SBA-15 immobilized ionic liquids remained satisfactory

  7. Industry

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

    2007-12-01

    This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of