The kinetics of diethylene glycol formation from bis-hydroxyethyl terephthalate with antimony catalyst in the preparation of PET

Chen, Jong-Wu; Chen, Leo‐Wang

doi:10.1002/(sici)1099-0518(19990615)37:12<1797::aid-pola9>3.0.co;2-3

Cited by 24 publications

(26 citation statements)

References 10 publications

(10 reference statements)

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“…The signals produced by the ethylene and cyclohexylenedimethylene terephthalate units were sensitive to the sequence distribution at the level of triads and their analysis led to conclude that the microstructure of these copolyesters was random. Similar conclusions were derived from the analysis of 13 C NMR spectra recorded from commercial PE x C y T copolyesters prepared by melt polycondensation [ 132 ] and also from those obtained by ring opening polymerization of mixtures of ethylene terephthalate and cyclohexylenedimethylene terephthalate cyclic oligomers. [ 129,130 ] In these spectra, the signals due to carbonyl carbon and the non-protonated aromatic carbons split into four peaks due to sequence effects at the level of dyads (insets of Figure 11 ).…”

Section: Copolyesterssupporting

confidence: 77%

“…However, the main source of this kind of chain defects arises from the etherifi cation reaction involving two hydroxyethyl end groups, a process that takes place mostly along the fi rst reaction step. [ 9 ] This side reaction [ 2,10 ] is catalyzed by the presence of acids, [ 11 ] metals, [ 12,13 ] and is favored by the pressure exerted in this step. [ 14 ] The high fl exibility of the oxydiethylene units gives rise to a perceivable reduction in the glass transition temperature when they are present in signifi cant amounts.…”

Section: Chain Defects: Oxydiethylene Unitsmentioning

confidence: 99%

“…In fact in an NMR study reported by Kenwright et al, [ 29 ] it was observed that the hydroxyl end groups of PET were fully esterifi ed after 5 days of immersion of the sample in TFA at room temperature. On the other hand, Fox et al [ 30 ] used 13 C NMR for hydroxyl end-group quantitative determination. Conversely, acid end groups, which usually amount about 20 mol% of the total end groups of PET, are diffi cult to analyze by NMR.…”

Section: End Groupsmentioning

confidence: 99%

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Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

Ilarduya

Muñoz‐Guerra

2014

Macro Chemistry & Physics

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The use of NMR spectroscopy in solution to investigate the chemical structure of engineering poly(alkylene terephthalate)s such as poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT), and poly(butylene terephthalate) (PBT) is reviewed. Chemical defects present in the polyester chain, such as oxydialkylene units, as well as accompanying side products such as cyclic oligomers generated in the polycondensation, are well detected in 1H NMR spectra. The technique is also demonstrated to be effective for identifying, and even for quantifying in certain cases, the end groups of these polyterephthalates, including those that are generated in small amounts as a consequence of thermal degradation. The application of NMR to the study of the chemical microstructure of copolyesters derived from such polyterephthalates is also reviewed for its unique ability to determine comonomeric sequence lengths and degree of randomness (R). Copolyesters synthesized by either melt polycondensation or entropically driven ring opening polymerization, in addition to those prepared by solid‐state modification or melt blending, are the object of this review.

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Section: Copolyesterssupporting

confidence: 77%

Section: Chain Defects: Oxydiethylene Unitsmentioning

confidence: 99%

Section: End Groupsmentioning

confidence: 99%

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Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

Ilarduya

Muñoz‐Guerra

2014

Macro Chemistry & Physics

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“…Sb 2 O 3 is a catalyst which can be used for both steps in the PET synthesis and is known to minimize side reactions . The activation energy of BHET with antimony trioxide as catalyst is lower than without addition of any catalyst . Duh proposed a mechanism for the effect of the antimony catalyst on the solid‐state polycondensation of PET .…”

Section: Introductionmentioning

confidence: 99%

Reasons for the Discoloration of Postconsumer Poly(ethylene terephthalate) during Reprocessing

Berg

Schaefer

Koerner

et al. 2016

Macro Materials & Eng

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Gray and/or yellow discoloration may occur during repeated heating of poly(ethylene terephthalate) (PET). Both phenomena can cause problems in further application. In this work, the reasons for the discoloration of PET during reprocessing are investigated by physical and chemical analysis such as colorimetry, size exclusion chromatography, viscosimetry (ηinh.), inductively coupled plasma mass spectrometry, X‐ray photoelectron spectroscopy, and MALDI‐ToF‐MS analysis. It is found that the antimony content which originates from catalyst residues used in PET synthesis has high influence on the gray discoloration obtained during reprocessing of PET. Antimony ions are reduced to elementary antimony during heating to temperatures above 230 °C as proven by X‐ray photoelectron spectroscopy. The yellow discoloration is partially generated by polyamide contaminants which are used as barrier layers in PET packaging materials such as soft drink bottles. In conclusion, to prevent discoloration of postconsumer PET during reprocessing different methods such as oxidation of gray metallic antimony or sorting out of polyamide contaminants are needed.

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“…[196,197] The kinetic data are determined taking into account the approximation of Li et al [198] to a n th order kinetics approach, widely used for the modelling of PUs. [199][200][201] (4.9)…”

mentioning

confidence: 99%

Estudio de Nanocompuestos de Espumas de Poliuretano Reforzadas con Nanocargas en Base Carbono

Bernal¹,

Mar²

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A la meua familia AGRADECIMIENTOSQuisiera agradecer, en primer lugar, al Ministerio de Ciencia e Investigación por la financiación para la realización de esta Tesis, mediante la concesión de la Beca FPI.A mis directores de Tesis, Dra. Raquel Verdejo y Dr. Miguel Ángel López Manchado por darme la oportunidad de trabajar con vosotros. A Raquel, por todo lo que me has enseñado durante estos años y por todo el tiempo que me has dedicado. A Miguel Ángel por tus comentarios constructivos, tus consejos y tu paciencia.A mi tutor en la UPV, Prof. Vicente Amigò por toda la ayuda que me has brindado sin apenas conocerme.Al Prof. Miguel Ángel Rodríguez Pérez de la Universidad de Valladolid por darme la posibilidad de trabajar en tu grupo y aprender más sobre espumas.I would like to thank Prof. Anthony J. Ryan, from The University of Sheffield, and Prof. Isabelle Huynen, from Université Catholique de Louvain, for your support and interest on my work.A todos mis compañeros del grupo por todos los ánimos y las risas. A Mario, Lean, Laura Peponi, Nicoletta, Iván y Sami. A mis chicas, Nella, Nat y Lauris, por todos los buenos momentos juntas entre recetas de cocina, clases de punto y bailes Bollywood! Quiero agradecer especialmente a Nella por ser mi profesora de la vida durante estos años y por las largas tardes-noches compartidas en la oficina. Y a Mario, nuestro "chico guapo" por todo el apoyo y por esas "características limitantes" que nos unen.A todo el grupo de Cauchos, en especial a Juan, Irene, Marta y Pilar, por ser como sois y por todas esas celebraciones en el laboratorio con vino, callos, migas y pasteles. Y a Miguel Arroyo, por esas paellas "madrileñas" que me hacen sentir como en casa.A Rodri, Jose e Isabel Quijada por haberme dejado participar en vuestros trabajos, por todo lo que he aprendido con vosotros y por haber confiado en mí.Al grupo del CellMat de la Universidad de Valladolid por haberme acogido tan bien durante las semanas que he estado con vosotros. En especial a Samu, Sergio y a Eusebio por vuestra colaboración en mis experimentos de radioscopia y DMA.I would like to thank my dear friends Masa, AC and Susi, for our great times in Sheffield.A special thanks to Isabel and Margherita for taking care of me during those hard months in Louvain-la-Neuve and for your friendship. Grazie Margheri per le nostre pause caffè e tutti gli scherzi! A todos mis amigos que me habéis apoyado durante este tiempo y, aunque en "la terreta" siempre os he tenido cerca. Y gracias a todas las personas que me han ayudado durante estos años. RESUMENLas espumas de nanocompuestos poliméricos tienen un gran interés tanto en áreas tecnológicas como científicas. Esto es debido a la combinación de las excelentes propiedades de las nanopartículas y la tecnología de espumado, dando lugar al desarrollo de materiales ligeros y multifuncionales. Este tipo de sistemas se utilizan en aplicaciones de alto rendimiento tan diversas como biomedicina, electrónica, paneles estructurales y embalajes, entre otras.Esta Tesis está basada en el desarro...

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The kinetics of diethylene glycol formation from bis-hydroxyethyl terephthalate with antimony catalyst in the preparation of PET

Cited by 24 publications

References 10 publications

Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

Reasons for the Discoloration of Postconsumer Poly(ethylene terephthalate) during Reprocessing

Estudio de Nanocompuestos de Espumas de Poliuretano Reforzadas con Nanocargas en Base Carbono

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