Relevant bibliographies by topics / Polyester hydrolysis

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  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Polyester hydrolysis'

Author: Grafiati
Published: 2 June 2025
Last updated: 19 July 2025

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Journal articles on the topic "Polyester hydrolysis"

1

Kumagai, Shogo, Yuto Morohoshi, Guido Grause, Tomohito Kameda, and Toshiaki Yoshioka. "Pyrolysis versus hydrolysis behavior during steam decomposition of polyesters using 18O-labeled steam." RSC Advances 5, no. 76 (2015): 61828–37. http://dx.doi.org/10.1039/c5ra08577b.

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A method was developed to distinguish between hydrolysis and pyrolysis pathways in the steam degradation of various polyesters. Selectivity was shown to be strongly influenced by the polyester structure.
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Wang, Haizhen, Tianrui Zhang, Kaixiang Chen, Liangkun Long, and Shaojun Ding. "Biochemical Characterization and Polyester-Binding/Degrading Capability of Two Cutinases from Aspergillus fumigatus." Microorganisms 13, no. 5 (2025): 1121. https://doi.org/10.3390/microorganisms13051121.

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Two recombinant cutinases, AfCutA and AfCutB, derived from Aspergillus fumigatus, were heterologously expressed in Pichia pastoris and systematically characterized for their biochemical properties and polyester-degrading capabilities. AfCutA demonstrated superior catalytic performance compared with AfCutB, displaying higher optimal pH (8.0–9.0 vs. 7.0–8.0), higher optimal temperature (60 °C vs. 50 °C), and greater thermostability. AfCutA exhibited increased hydrolytic activity toward p-nitrophenyl esters (C4–C16) and synthetic polyesters. Additionally, AfCutA released approximately 3.2-fold more acetic acid from polyvinyl acetate (PVAc) hydrolysis than AfCutB. Quartz crystal microbalance with dissipation monitoring (QCM-D) revealed rapid adsorption of both enzymes onto polyester films. However, their adsorption capacity on poly (ε-caprolactone) (PCL) films was significantly higher than on polybutylene succinate (PBS) films, and was influenced by pH. Comparative modeling of catalytic domains identified distinct structural differences between the two cutinases. AfCutA possesses a shallower substrate-binding cleft, fewer acidic residues, and more extensive hydrophobic regions around the active site, potentially explaining its enhanced interfacial activation and catalytic efficiency toward synthetic polyester substrates. The notably superior performance of AfCutA suggests its potential as a biocatalyst in industrial applications, particularly in polyester waste bioremediation and sustainable polymer processing.
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Di Bisceglie, Federico, Felice Quartinello, Robert Vielnascher, Georg M. Guebitz, and Alessandro Pellis. "Cutinase-Catalyzed Polyester-Polyurethane Degradation: Elucidation of the Hydrolysis Mechanism." Polymers 14, no. 3 (2022): 411. http://dx.doi.org/10.3390/polym14030411.

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Polyurethanes (PU) are one of the most-used classes of synthetic polymers in Europe, having a considerable impact on the plastic waste management in the European Union. Therefore, they represent a major challenge for the recycling industry, which requires environmentally friendly strategies to be able to re-utilize their monomers without applying hazardous and polluting substances in the process. In this work, enzymatic hydrolysis of a polyurethane-polyester (PU-PE) copolymer using Humicola insolens cutinase (HiC) has been investigated in order to achieve decomposition at milder conditions and avoiding harsh chemicals. PU-PE films have been incubated with the enzyme at 50 °C for 168 h, and hydrolysis has been followed throughout the incubation. HiC effectively hydrolysed the polymer, reducing the number average molecular weight (Mn) and the weight average molecular weight (Mw) by 84% and 42%, respectively, as shown by gel permeation chromatography (GPC), while scanning electron microscopy showed cracks at the surface of the PU-PE films as a result of enzymatic surface erosion. Furthermore, Fourier Transform Infrared (FTIR) analysis showed a reduction in the peaks at 1725 cm−1, 1164 cm−1 and 1139 cm−1, indicating that the enzyme preferentially hydrolysed ester bonds, as also supported by the nuclear magnetic resonance spectroscopy (NMR) results. Liquid chromatography time-of-flight/mass spectrometry (LC-MS-Tof) analysis revealed the presence in the incubation supernatant of all of the monomeric constituents of the polymer, thus suggesting that the enzyme was able to hydrolyse both the ester and the urethane bonds of the polymer.
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Fu, Hao, Linbo Gong, and Shuling Gong. "A New Approach Utilizing Aza-Michael Addition for Hydrolysis-Resistance Non-Ionic Waterborne Polyester." Polymers 14, no. 13 (2022): 2655. http://dx.doi.org/10.3390/polym14132655.

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This work first synthesized a series of linear polyesters by step-growth polycondensation, then an amino-terminated hydrophilic polyether was grafted to the polyester as side-chains through aza-Michael addition to prepare a self-dispersible, non-ionic waterborne comb-like polyester (NWCPE). In contrast to traditional functionalization methods that usually require harsh reaction conditions and complex catalysts, the aza-Michael addition proceeds efficiently at room temperature without a catalyst. In this facile and mild way, the NWCPE samples with number-average molecular weight (Mn) of about 8000 g mol−1 were obtained. All dispersions showed excellent storage stability, reflected by no delamination observed after 6 months of storage. The NWCPE dispersion displayed better hydrolysis resistance than an ionic waterborne polyester, as was indicated by a more slight change in pH value and Mn after a period of storage. In addition, the film obtained after the NWCPE dispersion was cross-linked with the curing agent, it exhibited good water resistance, adhesion, and mechanical properties.
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Zhang, Heng, Xiao Ze Jiang, Xiao Yun Pan, et al. "Exploring the Effect of Molecular Components on Hydrolysis-Resistance Performance and Hydrophilicity of Amphiphilic Poly(Ester-Block-Ether) Copolymers." Materials Science Forum 848 (March 2016): 99–110. http://dx.doi.org/10.4028/www.scientific.net/msf.848.99.

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In this study, four poly (ester-block-ether) copolymers were synthesized via the macromolecular transesterification method from different hydrophobic polyester segments prepared from precursors, dimethyl terephthalate (DMT), ethylene glycol (EG), dimethyl-5-hydroxyisophthalate (DHIP) and neopentyl glycol (NPG), and hydrophilic polyether, polyethylene glycol (PEG) or polyetheramine (PEA). The hydrolysis-resistance performance at alkaline condition and hydrophilicity of these four synthetic poly (ester-block-ether) copolymers were characterized by hydrolysis degree and water solubility with Nuclear Magnetic Resonance (NMR) and UV-Absorption Spectroscopy. The results showed that the hydrolysis degree and water solubility of poly (ester-block-ether) copolymers were mainly dominated by the molecular components, the molecular weights of polyester and polyether chains, and the connecting bonds between polyester and hydrophilic chains. The hydrolysis degree was listed from high to low: P(DHIP-NPG)-b-PEA, P(DMT-NPG)-b-PEA, P(DMT-EG)-b-PEA, then P(DMT-EG)-b-PEG. The P(DHIP-NPG)-b-PEA copolymer possesses the best hydrolysis-resistance performance, the hydrolysis degree of which reached only 4.1% after hydrolysis for 14 days, meanwhile, it showed excellent adsorption property on polyester fabrics and the surfaces of the treated fabrics exhibited well hydrophilicity. This study provides a light to explore novel poly (ester-block-ether) copolymers with well hydrolysis-resistance performance and high hydrophilicity through precisely constructing their molecular components, and further extend their potential applications in special auxiliaries and intermediates.
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Kupczak, Maria, Anna Mielańczyk, and Dorota Neugebauer. "The Influence of Polymer Composition on the Hydrolytic and Enzymatic Degradation of Polyesters and Their Block Copolymers with PDMAEMA." Materials 14, no. 13 (2021): 3636. http://dx.doi.org/10.3390/ma14133636.

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Well-defined, semi-degradable polyester/polymethacrylate block copolymers, based on ε-caprolactone (CL), d,l-lactide (DLLA), glycolide (GA) and N,N′-dimethylaminoethyl methacrylate (DMAEMA), were synthesized by ring-opening polymerization (ROP) and atom transfer radical polymerization. Comprehensive degradation studies of poly(ε-caprolactone)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PCL-b-PDMAEMA) on hydrolytic degradation and enzymatic degradation were performed, and those results were compared with the corresponding aliphatic polyester (PCL). The solution pH did not affect the hydrolytic degradation rate of PCL (a 3% Mn loss after six weeks). The presence of a PDMAEMA component in the copolymer chain increased the hydrolysis rates and depended on the solution pH, as PCL-b-PDMAEMA degraded faster in an acidic environment (36% Mn loss determined) than in a slightly alkaline environment (27% Mn loss). Enzymatic degradation of PCL-b-PDMAEMA, poly(d,l-lactide)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PLA-b-PDMAEMA) and poly(lactide-co-glycolide-co-ε-caprolactone)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PLGC-b-PDMAEMA) and the corresponding aliphatic polyesters (PCL, PLA and PLGC) was performed by Novozyme 435. In enzymatic degradation, PLGC degraded almost completely after eleven days. For polyester-b-PDMAEMA copolymers, enzymatic degradation primarily involved the ester bonds in PDMAEMA side chains, and the rate of polyester degradation decreased with the increase in the chain length of PDMAEMA. Amphiphilic copolymers might be used for biomaterials with long-term or midterm applications such as nanoscale drug delivery systems with tunable degradation kinetics.
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Aneja, Arun, Karel Kupka, Jiří Militký, and Mohanapriya Venkataraman. "Kinetics of Hydrolytic Depolymerization of Textile Waste Containing Polyester." Fibers 12, no. 10 (2024): 82. http://dx.doi.org/10.3390/fib12100082.

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Textile products comprise approximately 10% of the total global carbon footprint. Standard practice is to discard apparel textile waste after use, which pollutes the environment. There are professional collectors, charity organizations, and municipalities that collect used apparel and either resell or donate them. Non-reusable apparel is partially recycled, mainly through incineration or processed as solid waste during landfilling. More than 60 million tons of textiles are burnt or disposed of in landfills annually. The main aim of this paper is to model the heterogeneous kinetics of hydrolysis of multicomponent textile waste containing polyester (polyethylene terephthalate (PET) fibers), by using water without special catalytic agents or hazardous and costly chemicals. This study aims to contribute to the use of closed-loop technology in this field, which will reduce the associated negative environmental impact. The polyester part of waste is depolymerized into primary materials, namely monomers and intermediates. Reaction kinetic models are developed for two mechanisms: (i) the surface reaction rate controlling the hydrolysis and (ii) the penetrant in terms of the solid phase rate controlling the hydrolysis. A suitable kinetic model for mono- and multicomponent fibrous blends hydrolyzed in neutral and acidic conditions is chosen by using a regression approach. This approach can also be useful for the separation of cotton/polyester or wool/polyester blends in textile waste using the acid hydrolysis reaction, as well as the application of high pressure and the neutral hydrolysis of polyester to recover primary monomeric constituents.
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Bengtsson, Jenny, Anna Peterson, Alexander Idström, Hanna de la Motte, and Kerstin Jedvert. "Chemical Recycling of a Textile Blend from Polyester and Viscose, Part II: Mechanism and Reactivity during Alkaline Hydrolysis of Textile Polyester." Sustainability 14, no. 11 (2022): 6911. http://dx.doi.org/10.3390/su14116911.

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Chemical recycling of textiles holds the potential to yield materials of equal quality and value as products from virgin feedstock. Selective depolymerization of textile polyester (PET) from regenerated cellulose/PET blends, by means of alkaline hydrolysis, renders the monomers of PET while cellulose remains in fiber form. Here, we present the mechanism and reactivity of textile PET during alkaline hydrolysis. Part I of this article series focuses on the cellulose part and a possible industrialization of such a process. The kinetics and reaction mechanism for alkaline hydrolysis of polyester packaging materials or virgin bulk polyester are well described in the scientific literature; however, information on depolymerization of PET from textiles is sparse. We find that the reaction rate of hydrolysis is not affected by disintegrating the fabric to increase its surface area. We ascribe this to the yarn structure, where texturing and a low density assures a high accessibility even without disintegration. The reaction, similar to bulk polyester, is shown to be surface specific and proceeds via endwise peeling. Finally, we show that the reaction product terephthalic acid is pure and obtained in high yields.
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Dong, Zhao Qin, and Guo Qiang Chen. "Alkaline Hydrolysis of Polyester in the Presence of Ionic Liquids." Advanced Materials Research 441 (January 2012): 661–65. http://dx.doi.org/10.4028/www.scientific.net/amr.441.661.

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The alkaline hydrolysis of polyester fabric in NaOH solution in the presence of several 1-alkyl-3-methylimidazolium bromine ionic liquids (ILs), CnMImBr (n=8, 12, 14, 16) was examined in comparison to the use of cetyltrimethyl ammonium bromide (CTAB) as an accelerant. The weight loss of polyester fabric was found to be greatly dependent on the concentrations of ILs and the length of alkyl groups in ILs. C14MImBr and C16MImBr exhibited good catalytic actions. The use of C16MImBr as an accelerator could endow polyester fabrics with slightly higher weight loss in comparison with CTAB. In the presence of C16MImBr, the activation energy of polyester hydrolysis reaction was slightly higher than that for the use of C14MImBr as a catalyst. In summary, the CnMImBr with long carbon chain can be employed as the novel accelerator for the weight reduction process of polyester fabrics.
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Cammarano, Aniello, Giovanna Luca, and Eugenio Amendola. "Surface modification and adhesion improvement of polyester films." Open Chemistry 11, no. 1 (2013): 35–45. http://dx.doi.org/10.2478/s11532-012-0135-x.

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AbstractFacile surface modification of polyester films was performed via chemical solutions treatment. Surface hydrolysis was carried out by means of sodium hydroxide solutions, leading to the formation of carboxylate groups. Three commercial polyester films of 100 μm in thickness were used in this work: AryLite™, Mylar™, and Teonex™, hydrolysis time being the main modification parameter. FTIR-ATR analysis, topography and contact angle (CA) measurements, surface free energy (SFE) and T-Peel adhesion tests were carried out to characterize the modified films. A quantitative estimate of the carboxylates surface coverage as a function of treatment time was obtained through a supramolecular approach, i.e. the ionic self-assembly of a tetracationic porphyrin chromophore onto the film surface. The surface free energy and critical surface tension of the hydrolyzed polyesters was evaluated by means of Zisman, Saito, Berthelot and Owens-Wendt methods. It was shown that NaOH solution treatment increases roughness, polarity and surface free energy of polymers. As a result, T-Peel strengths for modified Mylar™ and Teonex™ films were respectively 2.2 and 1.8 times higher than that for the unmodified films, whereas AryLite™ adhesion test failed.
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Dissertations / Theses on the topic "Polyester hydrolysis"

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Schmidt, Juliane, Ren Wei, Thorsten Oeser, et al. "Degradation of Polyester Polyurethane by Bacterial Polyester Hydrolases." Universität Leipzig, 2017. https://ul.qucosa.de/id/qucosa%3A21100.

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Polyurethanes (PU) are widely used synthetic polymers. The growing amount of PU used industrially has resulted in a worldwide increase of plastic wastes. The related environmental pollution as well as the limited availability of the raw materials based on petrochemicals requires novel solutions for their efficient degradation and recycling. The degradation of the polyester PU Impranil DLN by the polyester hydrolases LC cutinase (LCC), TfCut2, Tcur1278 and Tcur0390 was analyzed using a turbidimetric assay. The highest hydrolysis rates were obtained with TfCut2 and Tcur0390. TfCut2 also showed a significantly higher substrate affinity for Impranil DLN than the other three enzymes, indicated by a higher adsorption constant K. Significant weight losses of the solid thermoplastic polyester PU (TPU) Elastollan B85A-10 and C85A-10 were detected as a result of the enzymatic degradation by all four polyester hydrolases. Within a reaction time of 200 h at 70 °C, LCC caused weight losses of up to 4.9% and 4.1% of Elastollan B85A-10 and C85A-10, respectively. Gel permeation chromatography confirmed a preferential degradation of the larger polymer chains. Scanning electron microscopy revealed cracks at the surface of the TPU cubes as a result of enzymatic surface erosion. Analysis by Fourier transform infrared spectroscopy indicated that the observed weight losses were a result of the cleavage of ester bonds of the polyester TPU.
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Björquist, Stina. "Separation for regeneration : Chemical recycling of cotton and polyester textiles." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-12388.

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In 2015, 96.7 million tonnes of textile fibres were produced world-wide. Our high consumption of textiles leads to an increased amount of textile waste. In Sweden, the majority of used clothing and textiles are incinerated due to the lack of recycling techniques. A large amount of post-consumer textile waste is made from blended materials. One of the most common blends, used in as near as all workwear and service textiles, is cotton/polyester. To enable chemical recycling of such textiles, cotton and polyester must first be separated. The aim of this thesis was to separate the materials by depolymerizing the polyester using alkaline hydrolysis. The focus of the work was on how such a process should be performed without a catalyst, in order to result in both a high yield and a high purity of the cotton residue. In order to recycle the residue as a raw material for manufacturing of man-made cellulosic fibres, the cellulose chains in the cotton must also be maintained as unaffected as possible. The polyester in new sheets was completely depolymerized after 390 min at a temperature of 90ºC using a 10% sodium hydroxide concentration and a 1% material-to-liquor concentration. The separation using these conditions gave high yields (above 96%) of the cotton residue regardless of the material fineness used in the process. Furthermore, the separation performed on old sheets show that a pure cotton residue could be produced using higher material concentrations. It was shown that the cotton residue from old sheets, laundered around 50 times, had an intrinsic viscosity comparable to dissolving pulps used for viscose fibre spinning. This study concludes that alkaline hydrolysis without the use of a catalyst could be used to separate cotton and polyester in blended textiles. Furthermore, the findings show that cotton percentage in old sheets only decreased slightly after 50 launderings. Characterization of the materials using ATR FTIR spectroscopy indicate that an integrated textile recycling of hospital bed sheets could be performed since the sheets only contain cotton and polyester in all parts of the sheets.
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Schmidt, Juliane, Ren Wei, Thorsten Oeser, et al. "Effect of Tris, MOPS, and phosphate buffers on the hydrolysis of polyethylene terephthalate films by polyester hydrolases." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-207524.

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The enzymatic degradation of polyethylene terephthalate (PET) occurs at mild reaction conditions and may find applications in environmentally friendly plastic waste recycling processes. The hydrolytic activity of the homologous polyester hydrolases LC cutinase (LCC) from a compost metagenome and TfCut2 from Thermobifida fusca KW3 against PET films was strongly influenced by the reaction medium buffers tris(hydroxymethyl)aminomethane (Tris), 3-(N-morpholino)propanesulfonic acid (MOPS), and sodium phosphate. LCC showed the highest initial hydrolysis rate of PET films in 0.2 M Tris, while the rate of TfCut2 was 2.1-fold lower at this buffer concentration. At a Tris concentration of 1 M, the hydrolysis rate of LCC decreased by more than 90% and of TfCut2 by about 80%. In 0.2 M MOPS or sodium phosphate buffer, no significant differences in the maximum initial hydrolysis rates of PET films by both enzymes were detected. When the concentration of MOPS was increased to 1 M, the hydrolysis rate of LCC decreased by about 90%. The activity of TfCut2 remained low compared to the increasing hydrolysis rates observed at higher concentrations of sodium phosphate buffer. In contrast, the activity of LCC did not change at different concentrations of this buffer. An inhibition study suggested a competitive inhibition of TfCut2 and LCC by Tris and MOPS. Molecular docking showed that Tris and MOPS interfered with the binding of the polymeric substrate in a groove located at the protein surface. A comparison of the Ki values and the average binding energies indicated MOPS as the stronger inhibitor of the both enzymes.
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Bollinger, Alexander [Verfasser], Karl-Erich [Gutachter] Jaeger, and Michael [Gutachter] Feldbrügge. "Novel carboxylic ester hydrolases from marine hydrocarbonoclastic bacteria - insights into organic solvent tolerance, substrate promiscuity and polyester hydrolysis / Alexander Bollinger ; Gutachter: Karl-Erich Jaeger, Michael Feldbrügge." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2020. http://d-nb.info/1217480315/34.

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Oliveux, Géraldine. "Influence des conditions d'hydrolyse sous-critique sur le recyclage des matériaux composites fibres de verre / résine polyester insaturé : influence des conditions et de la structure de la résine sur les cinétiques réactionnelles." Nantes, 2012. http://www.theses.fr/2012NANT2110.

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Un procédé d’hydrolyse en conditions batch est étudié pour rompre les liaisons ester de résines polyester insaturé et réticulé au styrène, matrices de matériaux composites renforcés de fibres de verre. Des conditions sous-critiques biphasiques apparaissent adaptées compte tenu de la chimie en jeu. La réaction d’hydrolyse suit en effet un mécanisme Aac2 et nécessite donc des conditions favorables à la réalisation de réactions ioniques, à savoir en particulier un produit ionique et une constante diélectrique relative de l’eau suffisants. Elle permet de récupérer en particulier les monomères d’origine de la résine. Mais ceux-ci subissent également des réactions secondaires ioniques. Ce traitement par hydrolyse affecte par ailleurs la qualité des fibres de verre récupérées. Elles sont corrodées, perdant ainsi une partie de leurs propriétés mécaniques, et nécessitent une phase de rinçage pour les débarrasser des substances organiques résiduelles. Des conditions ont cependant pu être identifiées comme permettant de minimiser la dégradation de leurs propriétés mécaniques. Ces conditions permettent également un taux de récupération maximal en monomères de la résine. Ainsi en moins d’une heure à 275°C, il est possible de rompre quasiment toutes les liaisons ester de la résine. Prolonger la durée de traitement ne fait que permettre aux réactions secondaires de se poursuivre. Un fonctionnement semi-continu s’avère indispensable pour minimiser les réactions secondaires et éviter l’étape ultérieure de rinçage des fibres. Il peut permettre par ailleurs une dégradation moins importante de ces dernières<br>A hydrolysis process in batch conditions is applied to break ester bonds of unsaturated polyester resins, crosslinked with styrene, as matrices of composite materials reinforced with glass fibres. Subcritical two-phase conditions appear adapted in view of the involved chemistry. The hydrolysis reaction follows in fact an Aac2 mechanism and requires then conditions enhancing ionic reactions, that is to say in particular sufficient values of the ionic product and of the relative dielectric constant of water. It allows the recovery of the initial monomers of the resin. But the latter’s are subjected to secondary ionic reactions. This hydrolysis treatment also affects the quality of the recovered glass fibres. They are corroded, loosing thus some of their mechanical properties, and require a washing phase to remove residual organic components. Conditions have however been identified as allowing minimizing the degradation of their mechanical properties. Those conditions also allow a maximum recovery rate of the initial monomers of the resin. Thus in less than an hour, it is possible to break almost all the ester bonds of the resin. A longer treatment time only allows secondary reactions to continue. A semi-continuous process appears to be essential to minimize secondary reactions and avoid the washing post-treatment of the fibres. It can also allow a less important degradation of them
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Marten, Elke. "Korrelationen zwischen der Struktur und der enzymatischen Hydrolyse von Polyestern." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959804153.

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Pullen, Deborah. "The hydrolytic stability of self-reinforcing polyesters." Thesis, Coventry University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279325.

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Welzel, Katharina. "Einfluss der chemischen Struktur auf die enzymatische Hydrolyse von Polyester-Nanopartikeln." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968015271.

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Bear, Marie-Maud. "Élaboration de poly (β-hydroxyacides) optiquement actifs à architecture controlée : accès par voies chimiques et/ou biologiques". Paris 12, 1998. http://www.theses.fr/1998PA120034.

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Les deux poles conducteurs de notre travail de recherche ont ete la chiralite, parce qu'il est possible a travers elle de controler la structure configurationnelle du polymere et donc certaines de ses proprietes, et les ressources de la biomasse, pour elaborer des polyesters optiquement actifs, pouvant etre degrades par simple hydrolyse, pour des applications de liberation controlee. Pour cela, nous avons emprunte a la nature differents systemes, d'une part un organisme complet, en l'occurrence une bacterie capable de produire des polyesters fonctionnalises et d'autre part, un enzyme extrait d'un micro-organisme pour preparer par biotransformation de nouveaux precurseurs chiraux et d'acceder ainsi a de nouveaux polymeres optiquement actifs. La synthese de derives du poly(acide -malique) comportant un deuxieme centre de chiralite en groupement lateral dans l'unite de repetition a ete realisee afin de mieux comprendre comment la structure chimique et la configuration du groupement ester lateral intervenaient dans l'organisation du polymere, d'analyser par rmn du carbone 13 les stereosequences des differents stereocopolymeres et de disposer de polymeres optiquement actifs possedant des structures bien definies. Grace a la 3-methylaspartase, enzyme extrait de clostridium tetanomorphum, nous avons pu obtenir differents stereoisomeres de l'acide 3-methylaspartique et ainsi parvenir a un poly(acide 3-methylmalique) optiquement actif et soluble en milieu aqueux. Nous avons aussi montre que ce polymere etait hydrolysable et non toxique et donc valorisable par des applications therapeutiques. Nous avons ainsi utilise la famille des polymeres derives du poly(acide -malique) pour preparer des micelles macromoleculaires totalement degradables. Dans le dernier chapitre, nous avons exploite la possibilite de synthese macromoleculaire par des micro-organismes. De nombreuses bacteries, sous contrainte physiologique, detournent le cycle de krebs et donc la respiration cellulaire vers la production et le stockage de polyesters optiquement actifs et de masse elevee. Nous avons choisi des substrats portant des insaturations pour faire synthetiser des polymeres fonctionnalises et donc modifiables chimiquement. La souche bacterienne utilisee, pseudomonas oleovorans, est vraiment particuliere et reflete bien la biodiversite des organismes vivants.
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Lindström, Frida. "Chemical and physical changes in PET fibres due to exhaust dyeing : Issues in thermo-mechanical recycling of dyed PET textiles." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-14772.

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Polyethylene terephthalate (PET) is the most used fibre in the textile industry. PET is also used in other products, e.g. soft-drink bottles and food packaging. Approximately 60% of the globally produced PET is intended for production of textile fibres and the demand for polyester fibres have steadily increased over the last decade. Yet, most of the recycled PET fibres are produced from discarded bottles and not discarded textiles even though the generation of textile waste is increasing year by year. The importance of finding efficient recycling routes for discarded PET textiles is obvious. In thermo-mechanical recycling the thermoplastic characteristic of PET is utilized to re-melt and re-form PET waste into new valuable products. Today, this is used for bottle-to-fibre recycling but not for fibre-to-fibre recycling. The main research question asked in this Master thesis is if the process of exhaust dyeing compromise the possibility to recycle PET textiles through remelt spinning. It is believed that PET degradation through hydrolysis may occur during dyeing. The degradation behaviour of PET has been widely studied. However, degradation during exhaust dyeing has not been investigated.   The process parameters temperature, time and number of dyeing cycles have been investigated. Also, possible effects of different auxiliary chemicals have been studied. Dyeing and characterisation of two PET fabrics with filaments of different titer was performed in order to investigate if the filament titer is also a parameter to consider.   Tensile testing and surface characterisation through demand absorbency test showed that the filament titer seems to affect how the tensile and moisture related properties change due to dyeing. Differential scanning calorimetry showed that the crystallisation rate is affected by the dyeing process. This can be an effect of formation of shorter PET chains during dyeing. The auxiliary chemicals have been shown to be the most critical factor in changes of the crystallisation behaviour. Fourier-Transform infrared spectroscopy indicated that chain scission has occurred during dyeing.   The results have shown that the exhaust dyeing process causes changes in tensile properties, moisture related properties, degree of crystallinity as well as crystallisation behaviour. DSC and FTIR results indicate chain scission. Based on the results it cannot be concluded if the changes are large enough to compromise the possibility to recycle PET textiles thermo-mechanically. Further research is required in order to correlate the observed changes with possible problems in thermomechanical recycling of dyed PET textiles.
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Book chapters on the topic "Polyester hydrolysis"

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Gonsalves, Kenneth E., and Xiaomao Chen. "Chain Structure and Hydrolysis of Nonalternating Polyester Amides." In ACS Symposium Series. American Chemical Society, 1994. http://dx.doi.org/10.1021/bk-1994-0545.ch015.

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Franco, Renan Louro Cardoso, Carsten Eichert, Charlotte Lücking, Lars Biermann, Mandy Paschetag, and Stephan Scholl. "revolPET®: An Innovative “Back-to-Monomer” Recycling Technology for the Open Loop Value Chain of PET and Polyester Composite Packaging and Textiles." In Lecture Notes in Mechanical Engineering. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28839-5_20.

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AbstractNowadays there is a need for innovative solutions for composite materials in the packaging and textile sectors. These are formed by multilayer structures that improve technical performance however complicates recycling. Consequently, they are mostly sent to energy recovery or downgrade recycling processes. To avoid this, new recycling technologies are needed.The innovative “back-to-monomer” recycling technology “revolPET®” represents a solution for this challenge. In the process, the polyethylene terephthalate (PET) is selectively depolymerized to recover the monomers ethylene glycol (EG) and terephthalic acid (TA) for a new PET production. By an alkaline hydrolysis, the PET reacts continuously with a strong base in a twin-screw extruder. The average residence time in the extruder is less than one minute with a process yield up to 95%. Due to the mild depolymerization conditions, the other polymers remain chemically unchanged and can be easily separated. The produced monomers are regained in virgin quality and can achieve a 33% reduction on the greenhouse gases emissions if compared with the crude oil production route.In this contribution, the technology on a pilot scale as well as the results of the first scale-up investigations are presented and discussed with respect to technical maturity and environmental benefit.
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Riepe, G., N. Chakfé, M. Morlock, A. Schröder, and H. Imig. "Langzeitverhalten von Gefäßprothesen im Menschen — Degeneration des Polyesters durch Hydrolyse." In Hefte zur Zeitschrift „Der Unfallchirurg“. Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59731-2_18.

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Pickett, James E. "Hydrolysis Kinetics and Lifetime Prediction for Polycarbonate and Polyesters in Solar Energy Applications." In Service Life Prediction of Exterior Plastics. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06034-7_3.

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Guebitz, Georg M. "Hydrolases in Polymer Chemistry: Part III: Synthesis and Limited Surface Hydrolysis of Polyesters and Other Polymers." In Advances in Polymer Science. Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/12_2010_89.

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Krynauw, Hugo, Lucie Bruchmüller, Deon Bezuidenhout, Peter Zilla, and Thomas Franz. "Constitutive Effects of Hydrolytic Degradation in Electro-Spun Polyester-Urethane Scaffolds for Soft Tissue Regeneration." In Tissue Engineering. Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-007-7073-7_3.

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Kreua-ongarjnukool, Narumol, Nopparuj Soomherun, Saowapa Thumsing Niyomthai, and Sorayouth Chumnanvej. "Aliphatic Polyester Nanoparticles for Drug Delivery Systems." In Smart Drug Delivery [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100977.

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Drug delivery systems using aliphatic polyester nanoparticles are usually prepared via an emulsion process. These nanoparticles can control drug release and improve pharmacokinetics. Aliphatic polyesters are linear polymers containing ester linkages, showing sensitivity to hydrolytic degradation. The byproducts then promote autocatalytic degradation. These byproducts could enter the Krebs cycle and be eliminated from the body, resulting in the high biocompatibility of these nanoparticles. The properties of these polyesters are linked to the drug release rate due to biodegradation, i.e., polymer crystallinity, glass transition temperature, polymer hydrophobicity, and molecular weight (MW), all of which relatively influence hydrolysis. Mathematical equations have been used to study the factors and mechanisms that affect drug dissolution compared to experimental release data. The equations used as models for predicting the kinetics of drug release include the zero-order, first-order, Higuchi, Hixson-Crowell, and Korsmeyer-Peppas equations. Aliphatic polyester-based controlled drug delivery has surrounded much of the current activity in the estimation parameters of nanoparticles and stimulated additional research. Polymeric nanoparticles have potential in a wide range of applications, such as in biotechnology, vaccine systems, and the pharmaceutical industry. The main goal of this chapter is to discuss aliphatic polyester nanoparticles as drug carrier systems.
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Hayavadana, J. "Degradation of Polyester Partially Oriented Yarns through Alkaline Hydrolysis Process: A Recent Study." In New Approaches in Engineering Research Vol. 12. Book Publisher International (a part of SCIENCEDOMAIN International), 2021. http://dx.doi.org/10.9734/bpi/naer/v12/12313d.

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Puton, Bruna Maria Saorin, Julia Lisboa Bernardi, Andressa Franco Denti, et al. "Immobilization of enzymatic extract in polyester fiber emulsified with polyurethane resin." In A LOOK AT DEVELOPMENT. Seven Editora, 2023. http://dx.doi.org/10.56238/alookdevelopv1-163.

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The objective of this work was to evaluate the immobilization of lipolytic and pectinolytic enzymatic extracts in a Polyester Fiber Emulsified with Polyurethane Resin (FPERP) support without and with functionalization with glutaraldehyde. In the first method, the support was emulsified with the enzymatic extract and then the shape of the immobilized was determined before the completion of the polymerization, and could be flat, coiled or double-layered. In the second method, the functionalization of PFRP with glutaraldehyde was performed before immobilization. The esterification activity and operational stability of lipolytic and pectinolytic immobilizes were determined by the synthesis of ethyl oleate and hydrolysis of citrus pectin, respectively. The immobilization of the lipolytic extract in support of PFRP functionalized with 50 and 25% glutaraldehyde resulted in immobilized patients with activity of 28.05 and 15.52 U/g, respectively. On the other hand, the immobilized without functionalization presented higher activity in the form of a double layer (132.17 U/g). The immobilization of the pectinolytic extract resulted in immobilizations with exo-polygalacturonase (exo-PG) and pectinmethylesterase (PME) activity of 1.78 and 12.34 U/g, respectively, for the double-layer immobilized. Regarding operational stability, the immobilized did not present satisfactory values, possibly due to the inefficiency of the polyurethane resin as a support for enzymatic immobilization on the fiber.
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Acosta Ortiz, Ricardo. "Hydrolytic stability of unsaturated polyesters." In Applications of Unsaturated Polyester Resins. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-323-99466-8.00007-1.

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Conference papers on the topic "Polyester hydrolysis"

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Mcilvaine, Josh, and Malika Warner. "Next Generation in Hydrolysis Resistance Polyester (PBT) for Electrical Connectors and Components." In SAE 2014 World Congress & Exhibition. SAE International, 2014. http://dx.doi.org/10.4271/2014-01-1042.

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Richaud, Emmanuel, Isabelle Derue, Pierre Gilormini, et al. "Hydrolytic ageing of polyester networks - Role of a plasticizer." In TIMES OF POLYMERS (TOP) AND COMPOSITES 2014: Proceedings of the 7th International Conference on Times of Polymers (TOP) and Composites. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4876785.

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