Degradation of nylon-6 in ethylene glycol

Huczkowski, P.; Kapko, Jerzy; Olesiak, R

doi:10.1016/0032-3861(78)90177-5

Cited by 21 publications

(11 citation statements)

References 11 publications

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“…The differences in conversion rates thus cannot be attributed to different reaction conditions. These results are in agreement with previous reports of PA-6 glycolysis, showing a strong increase of reaction rates when H 3 PO 4 is used while ZnAc 2 had only a slight effect [16]. The difference between ZnCl 2 and ZnAc 2 is in part a consequence of the solubility of ZnAc 2 in water, which is several orders of magnitude lower than that of ZnCl 2 (ZnCl 2 = 615 g per 100 ml, ZnAc 2 = 44.6 g/mol) [17].…”

supporting

confidence: 93%

Degradation of polyamide‐6 by using metal salts as catalyst

Klun¹,

Kržan²

2002

Polymers for Advanced Techs

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Polyamide‐6 (PA‐6) is a widely used polycondensation polymer that can be recycled by hydrolysis to its monomer ϵ‐caprolactam. The reaction is normally catalyzed by mineral acids. Using microwaves as the source of heating, zinc chloride, acetate and triflate were evaluated as non‐acid catalysts for the reaction. Gravimetric and electron spray ionization mass spectrometry analysis of reaction products showed ZnCl2 as the most effective salt catalyst. A 50wt% (versus PA‐6) addition gave 75% water‐soluble, low‐molecular‐weight oligomers, which is approximately 25% lower than when using phosphoric acid. The triflate salt was effective only when used as an addition to a mineral acid, whereas the acetate was ineffective. FTIR and NMR spectroscopy of degradation products showed that dissociated ions from ZnCl2 bind to the amide group of the polymer. Using the triflate salt no such interaction could be observed, indicating that the degradation and catalysis mechanisms differ with the chloride and triflate salt. Five water‐stable lanthanide triflates showed no catalytic effect on the reaction. Copyright © 2003 John Wiley & Sons, Ltd.

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confidence: 93%

Degradation of polyamide‐6 by using metal salts as catalyst

Klun¹,

Kržan²

2002

Polymers for Advanced Techs

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“…The free carboxylic acid and carboxylic acid were esterified with ethylene glycol; the major products were caprolactam, N-(5-hydroxy-3-oxa-pentyl)-caprolactam, N,N'-ethylene-di(caprolactam), and N-(2-hydroxyethyl)-caprolactam, and linear oligomers were reported. Huczkowski et al investigated the glycolysis of nylon 6 in boiling ethylene glycol with and without a catalyst, resulting in oligoamides containing amino-and hydroxyl end-groups [230,231]. Holland and Hay presented the thermal degradation of nylon 6 and nylon 6,6 to produce a crosslinking formation and non-volatile char [232].…”

Section: Textile Recycling Using Glycolysismentioning

confidence: 99%

Possibility Routes for Textile Recycling Technology

et al. 2021

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The fashion industry contributes to a significant environmental issue due to the increasing production and needs of the industry. The proactive efforts toward developing a more sustainable process via textile recycling has become the preferable solution. This urgent and important need to develop cheap and efficient recycling methods for textile waste has led to the research community’s development of various recycling methods. The textile waste recycling process can be categorized into chemical and mechanical recycling methods. This paper provides an overview of the state of the art regarding different types of textile recycling technologies along with their current challenges and limitations. The critical parameters determining recycling performance are summarized and discussed and focus on the current challenges in mechanical and chemical recycling (pyrolysis, enzymatic hydrolysis, hydrothermal, ammonolysis, and glycolysis). Textile waste has been demonstrated to be re-spun into yarn (re-woven or knitted) by spinning carded yarn and mixed shoddy through mechanical recycling. On the other hand, it is difficult to recycle some textiles by means of enzymatic hydrolysis; high product yield has been shown under mild temperatures. Furthermore, the emergence of existing technology such as the internet of things (IoT) being implemented to enable efficient textile waste sorting and identification is also discussed. Moreover, we provide an outlook as to upcoming technological developments that will contribute to facilitating the circular economy, allowing for a more sustainable textile recycling process.

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“…The reports on the glycolysis of nylon 6.6 are rather limited. Up to now, the glycolysis of nylon 6 was studied more accurately [26,27]. Kim et al [5] examined the degradation mechanism of polyamide 6.6 by ethylene glycol that is based on the decomposition of the model compound, namely, N,Nhexamethylenebis(hexamide).…”

Section: Introductionmentioning

confidence: 99%

A New Approach to Chemical Recycling of Polyamide 6.6 and Synthesis of Polyurethanes with Recovered Intermediates

et al. 2018

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A new efficient method for the chemical decomposition of polyamide 6.6 by the glycolysis and amino-glycolysis processes was proposed. The glycolysis was conducted using the mass excess of ethylene glycol (EG) as a decomposing agent in the presence of a catalyst. Also, a mixture of EG and triethylenetetramine was used as another decomposing agent in the aminoglycolysis process. The described process of decomposition did not require the use of elevated pressure. The hydroxyl and amine numbers, rheology behavior and the presence of characteristic chemical groups in the obtained glycolysates and aminoglycolysates were determined in order to characterize the reaction products. The decomposition products were defined as non-Newtonian fluids that could be described by suitable mathematical models. The conducted studies showed that the properties of the obtained intermediates depend on the mass excess of the decomposing agent used. The resulting semiproducts are suitable for reusing in the synthesis of polyurethanes, which has been confirmed by the exemplary synthesis. In the reaction, 10 and 15 wt% of commercial polyol were replaced with the recovered intermediates.

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Degradation of nylon-6 in ethylene glycol

Cited by 21 publications

References 11 publications

Degradation of polyamide‐6 by using metal salts as catalyst

Degradation of polyamide‐6 by using metal salts as catalyst

Possibility Routes for Textile Recycling Technology

A New Approach to Chemical Recycling of Polyamide 6.6 and Synthesis of Polyurethanes with Recovered Intermediates

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