Structure of poly(ε‐caprolactam) obtained in anionic bulk polymerization

Mateva, R.; Delev, O.; Kaschcieva, E.

doi:10.1002/app.1995.070581301

Cited by 14 publications

(6 citation statements)

References 17 publications

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“…Therefore, the melting point of the polymer reflects the crystalline structure of S‐PA6. Figures 5c and 6c show that the melting point of PA6 decreased with the increase in the initial polymerization temperature because of the decrease in the crystalline perfection with increasing temperature 26. Increasing the initial polymerization temperature resulted in the synthesis of PA6 with a less perfect crystalline structure because of enhanced branching at high temperatures.…”

Section: Resultsmentioning

confidence: 96%

Optimizing conditions for anionic polymerization of caprolactam for inkjetting

et al. 2010

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ABSTRACT:This work deals with a study of polymerization condition variables such as catalyst concentration, activator concentration, and initial polymerization temperature in the anionic polymerization of ε-caprolactam. Ethylmagnesium bromide (EtMgBr) and sodium hydride (NaH) were used to make the catalyst compositions. N-acetylcaprolactam was used as the activator. The polymerization conditions were optimized for both catalysts. The final properties (i.e., monomer conversion, melting point, and molecular weight) of synthesized polymers were compared. ε-Caprolactam magnesium bromide showed a big advantage over sodium ε-caprolactamate in terms of solidification time and also final properties of synthesized polymers. It was found possible to reduce the solidification half-time to less than 1 min. C 2010 Wiley Periodicals, Inc. Adv Polym Techn 29: 226-236, 2010; View this article online at wileyonlinelibrary.com.

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Section: Resultsmentioning

confidence: 96%

Optimizing conditions for anionic polymerization of caprolactam for inkjetting

et al. 2010

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“…In 1967, the synthesis of CBC as an intermediate for the synthesis of lysine was disclosed in a Japanese patent . As difunctional N -acyllactam, CBC was used successfully as activator for the anionic ring-opening polymerization of various lactams. − In 1996, BASF claimed the use of a large variety of heterocyclic substances, among them CBC, as activators for organic peroxides in washing and bleaching agents . Since 2000, DSM and others have filed patents concerning the preparation of CBC and its use as coupling agent, chain extender, or cross-linker. − …”

Section: Resultsmentioning

confidence: 99%

Isocyanate-Free Route to Caprolactam-Blocked Oligomeric Isocyanates via Carbonylbiscaprolactam- (CBC-) Mediated End Group Conversion

et al. 2003

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Blocked isocyanate functional oligomers and liquid rubbers are prepared by a novel, solventfree carbonylbiscaprolactam (CBC) mediated end group conversion reaction of amine-terminated oligodimethylsiloxanes (PDMS) and oligopropyleneoxides (PPO), with molar masses varying between 400 and 3140 g/mol, and of hydroxy-terminated oligoethylene oxide (PEG), oligopropyleneoxide (PPO) and oligotetrahydrofuran (PTHF), with molar masses of around 1000 g/mol. The key reaction is the carbonylbiscaprolactam (CBC) mediated amino or hydroxy end group conversion yielding carbamoyl caprolactam functional polymers, without requiring addition of either phosgene or isocyanates. The quantitative CBC conversion of amine end groups occurred in bulk at 100°C in the absence of catalysts, yielding N-carbamoyl caprolactam terminated oligomers and caprolactam (ring elimination, pathway RE). The reaction of hydroxy end groups at 100 to 150°C in the presence of catalysts such as zirconium alcoholates, magnesium bromide or dibutyltindilaurate (DBTDL) produced N-carbamoyl caprolactam end groups via nucleophilic attack of the hydroxy group at one of the CBC caprolactam rings and subsequent ring opening (ring opening, pathway RO). The CBC reactions were monitored by means of ReactIR, 1 H NMR and 13 C NMR spectroscopy. The molecular masses of the oligomers and liquid rubbers with caprolactam-blocked isocyanate end groups were measured by means of MALDI-ToF mass spectroscopy and size exclusion chromatography (SEC). The thermal behavior and deblocking temperatures of the caprolactam-blocked isocyanates obtained were examined by means of thermogravimetric analysis (TGA).

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“…A first explanation is connected to the fact that, the more the temperature increases, the more the mobility of the macromolecules is favored, resulting in a lower possibility of forming crystallites [83]. A second explanation is that branch points disturb the formation of crystals and, therefore, reduce the degree of crystallinity [91].…”

Section: Effect Of the Polymerization Temperature On Crystallinitymentioning

confidence: 99%

Thermoplastic Composite Materials Approach for More Circular Components: From Monomer to In Situ Polymerization, a Review

et al. 2022

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To move toward eco-sustainable and circular composites, one of the most effective solutions is to create thermoplastic composites. The strong commitment of world organizations in the field of safeguarding the planet has directed the research of these materials toward production processes with a lower environmental impact and a strong propensity to recycle the polymeric part. Under its chemical properties, Nylon 6 is the polymer that best satisfies this specific trade-off. The most common production processes that use a thermosetting matrix are described. Subsequently, the work aimed at investigating the use of thermoplastics in the same processes to obtain comparable performances with the materials that are currently used. Particular attention was given to the in situ anionic polymerization process of Nylon 6, starting from the ε-caprolactam monomer. The dependencies of the process parameters, such as temperature, time, pressure, humidity, and concentration of initiators and activators, were therefore investigated with reference to the vacuum infusion technique, currently optimized only to produce thermosetting matrix composites, but promising for the realization of thermoplastic matrix composite; this is the reason why we chose to focus our attention on the vacuum infusion. Finally, three production processes of the polymeric matrix and glass fiber composites were compared in terms of carbon footprint and cumulative energy demand (CED) through life-cycle assessment (LCA).

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Structure of poly(ε‐caprolactam) obtained in anionic bulk polymerization

Cited by 14 publications

References 17 publications

Optimizing conditions for anionic polymerization of caprolactam for inkjetting

Optimizing conditions for anionic polymerization of caprolactam for inkjetting

Isocyanate-Free Route to Caprolactam-Blocked Oligomeric Isocyanates via Carbonylbiscaprolactam- (CBC-) Mediated End Group Conversion

Thermoplastic Composite Materials Approach for More Circular Components: From Monomer to In Situ Polymerization, a Review

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