The cause of the grey discoloration of PET prepared by the use of antimony-catalysts. (polyethylene terephthalate): An article from: Polymer Engineering and Science
Book Details
Author(s)Shaul M. Aharoni
PublisherSociety of Plastics Engineers, Inc.
ISBN / ASINB00098A7D8
ISBN-13978B00098A7D0
AvailabilityAvailable for download now
MarketplaceUnited States 🇺🇸
Description
This digital document is an article from Polymer Engineering and Science, published by Society of Plastics Engineers, Inc. on July 1, 1998. The length of the article is 7714 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
From the author: Heating three antimony catalysts with several glycols and other model compounds in open and sealed vessels with various degrees of oxygen availability was followed by analyses of the volatile products in the head-space and of the nonvolatile products. Bis(hydroxyethylene terephthalate)(Bis-HET) and terephthalic acid (TA) plus ethylene glycol (EG) were separately polymerized to poly(ethylene terephthalate)(PET) and TA plus triethylene glycol (TEG) was polymerized to poly(triethyleneglycol terephthalate) (PTEGT). Analyses of the polymers and of the model compounds revealed that: 1) Free glycols or the glycolate moieties in polyesters degrade upon heating in the presence of oxygen to produce equal amounts of CO and C[O.sub.2]. 2) In the presence of Sb(III) species, the CO oxidizes to C[O.sub.2] at elevated temperatures with the concomitant reduction of Sb(III) to very fine black particles of the elemental Sb(0). This is the cause for the grey discoloration of PET made with Sb-catalysts. The redox reaction starts at about 200 [degrees] C and is fully dominant at about 235 [degrees] C and above. 3) At temperatures lower than [approximately]200 [degrees] C, the Sb(III) usually converts to the white [Sb.sub.2][O.sub.3] and the CO does not oxidize the C[O.sub.2].
Citation Details
Title: The cause of the grey discoloration of PET prepared by the use of antimony-catalysts. (polyethylene terephthalate)
Author: Shaul M. Aharoni
Publication:Polymer Engineering and Science (Refereed)
Date: July 1, 1998
Publisher: Society of Plastics Engineers, Inc.
Volume: v38 Issue: n7 Page: p1039(9)
Distributed by Thomson Gale
From the author: Heating three antimony catalysts with several glycols and other model compounds in open and sealed vessels with various degrees of oxygen availability was followed by analyses of the volatile products in the head-space and of the nonvolatile products. Bis(hydroxyethylene terephthalate)(Bis-HET) and terephthalic acid (TA) plus ethylene glycol (EG) were separately polymerized to poly(ethylene terephthalate)(PET) and TA plus triethylene glycol (TEG) was polymerized to poly(triethyleneglycol terephthalate) (PTEGT). Analyses of the polymers and of the model compounds revealed that: 1) Free glycols or the glycolate moieties in polyesters degrade upon heating in the presence of oxygen to produce equal amounts of CO and C[O.sub.2]. 2) In the presence of Sb(III) species, the CO oxidizes to C[O.sub.2] at elevated temperatures with the concomitant reduction of Sb(III) to very fine black particles of the elemental Sb(0). This is the cause for the grey discoloration of PET made with Sb-catalysts. The redox reaction starts at about 200 [degrees] C and is fully dominant at about 235 [degrees] C and above. 3) At temperatures lower than [approximately]200 [degrees] C, the Sb(III) usually converts to the white [Sb.sub.2][O.sub.3] and the CO does not oxidize the C[O.sub.2].
Citation Details
Title: The cause of the grey discoloration of PET prepared by the use of antimony-catalysts. (polyethylene terephthalate)
Author: Shaul M. Aharoni
Publication:Polymer Engineering and Science (Refereed)
Date: July 1, 1998
Publisher: Society of Plastics Engineers, Inc.
Volume: v38 Issue: n7 Page: p1039(9)
Distributed by Thomson Gale
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