Effect of imides on the alkaline polymerisation of caprolactam

Šebenda, J.; Králíček, Jaroslav

doi:10.1135/cccc19580766

Cited by 43 publications

(8 citation statements)

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“…Since the discovery of rapid anionic polymerization of lactams in the 1950s, it has received considerable attention 1–9. Kralicek and Sebenda1–4 in the Institute of Macromolecular Chemistry in Prague and Mottos et al5–11 of Monsanto in the U.S.A. discovered massive cocatalytic influence of certain imides on the anionic polymerization of ϵ‐caprolactam. If an equivalent amount of N ‐acetylcaprolactam was added to sodium ϵ‐caprolactam, the rate of polymerization increased by several orders of magnitude.…”

Section: Introductionmentioning

confidence: 99%

Volume and process of care in high‐risk cancer surgery

Birkmeyer

Sun

Goldfaden

et al. 2006

Cancer

212

147

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The adult subventricular zone (SVZ) contains progenitors cells, which continually give rise to new neurons that migrate along the rostral migratory stream (RMS) to the olfactory bulbs (OB). Prokineticin receptor 2 (ProKR2) is a G‐protein‐coupled receptor that plays an essential role in this migration process. However, the identity of the prokr2‐expressing cells has not yet been clearly established. Here, we have characterized in detail the identity of the prokr2‐expressing cells in the SVZ/RMS/OB pathway in adult mice. In the SVZ, accumulation of prokr2 transcripts was detected in almost all migrating neuroblasts or type A cells as well as in a large population of their precursors, the rapidly dividing type C cells. Moreover, we observed that, in dissociated SVZ cells from Mash1::GFP postnatal mice, ProKR2 protein is also present in type C and type A cells. We found that, along the RMS and in the OB, prokr2 expression was restricted to migrating type A cells and was absent in astrocytes. Finally, we observed a highly marked decrease of prokr2 expression in Mash1−/− mutant mice, suggesting that this transcription factor directly or indirectly regulates prokr2 expression. Although the expression of ProKR2 in migrating type A cells is in good agreement with the essential role played by this receptor during this migration process, its expression in a large population of their progenitors suggests an additional function for ProKR2, providing novel insights into the role of ProKR2/ProK2 signalling in adult neurogenesis. J. Comp. Neurol. 512:232–242, 2009. © 2008 Wiley‐Liss, Inc.

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Section: Introductionmentioning

confidence: 99%

Volume and process of care in high‐risk cancer surgery

Birkmeyer

Sun

Goldfaden

et al. 2006

Cancer

212

147

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“…The mechanism of the anionic polymerization of B-caprolactam was clarified by Sebenda et al 5 • 6 and Sekiguchi et al 8 as shown in Table I. They clarified that the rate-determining step of the polymerization was the reaction oflactam-anion with acyl-lactam (eq ii in Table I).…”

Section: Kinetic Equationsmentioning

confidence: 99%

“…1 -4 Many studies on mechanism 5 -15 and kinetics 16 -2 7 of the anionic polymerization of s-caprolactam have been carried out. The fundamental major reaction mechanisms of the polymerization were clarified by Sebenda et al 5 • 6 and Sekiguchi et al 8 who found the rate-determining step of the polymerization to be the reaction of lactam-anion with acyl-lactam. This mechanism may be acceptable except the part of the formation of the intermediates.…”

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confidence: 99%

Synthesis of High Molecular Weight Nylon 6 by Anionic Polymerization of ε-Caprolactam. Mechanism and Kinetics

Ueda

Nakai

Hosoda

et al. 1997

Polym J

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“…Initiation and growth of the polymer chain are essentially a series of succeeding attacks of the lactamate anion [5] upon either [I51 or a terminal imide group. The peculiar characteristic of the activated aromatic halides is the fact that once the initiator [15] if formed, the polymerization is very rapid. However, formation of [15] is slow and determines the reaction rate.…”

Section: Mechanism Of the Polymerizationmentioning

confidence: 99%

Anionic polymerization of ε‐caprolactam with activated aromatic halide initiators

Matzner¹,

Robeson²,

Greff³

et al. 1972

Angew. Makromol. Chem.

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The reaction of 4,4'-dichlorodiphenylsulfone with the caprolactamate anion was investigated. The expected diamide derivative could not be isolated. Instead, high molecular weight polymer was obtained in the presence of excess &-caprolactam. I11 defined species resulted when the reaction was conducted in aprotic solvents.The initiation of the base-catalyzed polymerization of e-caprolactam with 4,4'dichlorodiphenylsulfone and other activated aromatic halides was then studied. The rate of polymerization is relatively slow compared to other known initiators. This is an advantage in casting operations where a finite pot life may be required. The results are rationalized in a proposed mechanism wherein the formation of the initiator is the rate determining factor.The anionically prepared Nylon 6 was characterized via several techniques such as gel permeation chromatography, light scattering and melt rheology. Mechanical properties were also determined. ZUSAMMENFASSUNG :Die Reaktion von 4,4'-Dichlordiphenylsulfon mit dem Caprolactamat-Anion wurde untersucht. Das erwartete Diamid-Derivat konnte nicht isoliert werden. Statt dessen wurde in Gegenwart von uberschiissigem e-Caprolactam ein Polymeres von hohem Molekulargewicht erhalten. Die Durchfiihrung der Reaktion in aprotischen Losungsmitteln gab ein schwierig zu definierendes Molekulgemisch. 4,4'-Dichlordiphenylsulfon und andere aktivierte aromatische Halogenide wurden als Starter fiir die Alkali-katalysierte Polymerisation von c-Caprolactam studiert. Die Bildung von Polymeren ist im Vergleich zu anderen bekannten Initiatoren verhiiltnismiiDig langsam. Das ist ein Vorteil in GieDverfehren, wo ein bestimmtes ,,Pot-Life" gefordert wird. Die Ergebnisse werden in einem vorgeschlagenen Reaktionsmechanismus, worin die Bildung des Starters der umsatzbestimmende Faktor ist, verstiindlich.Das anionisch hergestellte Nylon 6 wurde mit verschiedenen Techniken wie Gel-Permeations-Chromatographie, Lichtstreuung und SchmelzfluBverhalten charakterisiert. Die mechanischen Eigenschaften des Polymeren wurden ebenfalls bestimmt.

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Effect of imides on the alkaline polymerisation of caprolactam

Cited by 43 publications

References 0 publications

Volume and process of care in high‐risk cancer surgery

Volume and process of care in high‐risk cancer surgery

Synthesis of High Molecular Weight Nylon 6 by Anionic Polymerization of ε-Caprolactam. Mechanism and Kinetics

Anionic polymerization of ε‐caprolactam with activated aromatic halide initiators

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