Talk:Polyethylene terephthalate

message: PET is clearly a strictly alternating copolymer of 2 different monomers (ethylene glycol and terephthalate) and so this article's assertion that it is a homopolymer (introduction to the copolymers section) is wrong. Azo bob (talk) 15:11, 26 April 2009 (UTC)
thread_title:  Copolymer ''vs.'' homopolymer 

message: Can someone add a date when it was first developed and processed? Davidbod (talk) 02:01, 15 January 2008 (UTC)
thread_title:  Date/history 

message: Can somone explain more about the washing process of PET in recycling it? I think it would be nice to have more detail about the recycling process in general. I guess it kinda connects to the recycling bottles page, but it isn't that specific either.
All I get when I google is sites selling PET services =\
Enjone 03:30, 15 October 2007 (UTC)
thread_title:  Washing 

message: Just wanted some idea on amorphous PET and how it is different from PET in terms of applicatoions
Ankit
Amorphous PET is the clear form of PET. Most PET you will see (Bottles, film, etc.) is in the amorphous state. PET can be crystallized, but then it is opaque.  — Preceding unsigned comment added by 66.158.138.212 (talk) 13:04, 6 December 2012 (UTC)
thread_title:  Amorphous PET 

message: It says "See copolymers, below", but there's nothing below that on copolymers...
:I believe that was from before a re-organization of the article.  I've changed it to "above"...the link to the section was the intended mode of navigation, and thankfully, it still works. --Joel 21:42, 20 January 2006 (UTC)
thread_title:  Below? 

message: but if its published elsewhere then its not original reserch now, here in wikipedia, that is the meaning. lets have a section onm potential toxicity in the article.213.106.121.219 (talk) 01:27, 3 September 2009 (UTC)
replies: text: PET doesn't have products or by product as described above. The only by product of PET is Acetaldehyde, but only appears at plastizicing temperatures ( 260°C ~ 280°C and above). To do that you need to cut the PET molecular chain and this occurs by degradation. Molecular chain rupture can occurs by hydrolysis or thermal degradation at plastizicing temperatures or mechanical effects by shear stress into the extruder barrel caused by the plastizicing screw. I'dont know what is chemically occuring when you use additives. The additives can be the source of substances other than Acetaldehyde.  —Preceding unsigned comment added by 200.3.119.81 (talk) 15:21, 24 January 2008 (UTC)
thread_title:  Di(2-ethylhexyl) adipate original research moved to talk 

message: According to the "Non-Toxic Times", April 2004 published by Seventh Generation, Inc. PETE has been shown to leach Di(2-Ethylhexyl) adipate (CAS Number: 103-23-1) into water. Di(2-Ethylhexyl) adipate AKA Bis(2-ethylhexyl) adipate has been found to leach from drinking water bottles made from PETE particularly after bottles have been squeezed, scratched or washed with hot water. Deena Lilya was a graduate student at the University of Idaho when she did this research. Di(2-Ethylhexyl) adipate is a suspected human carcinogen.
http://www.seventhgeneration.com/site/apps/s/content.asp?c=coIHKTMHF&b=133099&ct=97028#3
http://www.findarticles.com/p/articles/mi_m1041/is_8_81/ai_105163668
Adrián Vega
::PET doesn't have products or by product as described above. The only by product of PET is Acetaldehyde, but only appears at plastizicing temperatures ( 260°C ~ 280°C and above). To do that you need to cut the PET molecular chain and this occurs by degradation. Molecular chain rupture can occurs by hydrolysis or thermal degradation at plastizicing temperatures or mechanical effects by shear stress into the extruder barrel caused by the plastizicing screw. I'dont know what is chemically occuring when you use additives. The additives can be the source of substances other than Acetaldehyde.  —Preceding unsigned comment added by 200.3.119.81 (talk) 15:21, 24 January 2008 (UTC)
thread_title: Potential hazards in food contact applications

message: I had moved the section reproduced below because of concerns about Original research.  I've bolded the statements that appeared to be of concern.  (The <== ==> section is also one I flagged; but, the bold doesn't seem to show up.)  I thought moving the discussion here was appropriate to see if more NPOV and Verifiability could be achieved.  My thoughts on the topic itself follow the moved section.
-----Start Moved Section------
===Potential hazards in food contact applications===
According to the "Non-Toxic Times", April 2004 published by Seventh Generation, Inc. PETE has been shown to leach Di(2-Ethylhexyl) adipate (CAS Number: 103-23-1) into water. Di(2-Ethylhexyl) adipate AKA Bis(2-ethylhexyl) adipate has been found to leach from drinking water bottles made from PETE particularly after bottles have been squeezed, scratched or washed with hot water. Deena Lilya was a graduate student at the University of Idaho when she did this research. Di(2-Ethylhexyl) adipate is a suspected human carcinogen.
http://www.seventhgeneration.com/site/apps/s/content.asp?c=coIHKTMHF&b=133099&ct=97028#3
http://www.findarticles.com/p/articles/mi_m1041/is_8_81/ai_105163668
===No hazards in food contact applications demonstrated===
Di(2-Ethylhexyl)adipate (DEHA) is neither inherent in PET as a raw material, nor a byproduct or decomposition product of PET. DEHA is a common plasticizer that is used in many plastic items but not in PET. Furthermore, the Swiss Federal Laboratories for Materials Testing and Research in their study (June 2003) on "Migration of organic components from polyethylene terephthalate (PET) bottles to water", carried out on new and reused plastic water bottles, did not find DEHA at concentrations significantly above the background levels detected in distilled water, indicating DEHA is unlikely to have migrated from the bottles. The study concluded that the levels of DEHA are distinctly below the World Health Organization guidelines for safe drinking water. 
http://www.sodis.ch/files/Report_EMPA.pdf
http://www.plasticsinfo.org/beveragebottles/apc_faqs.html
According to the report the bottles tested in the Sodis "Report_EMPA.pdf" above orginated from the countries of Honduras, Nepal and Switzerland.  When Deena Lilya investigated PET bottle leachates she was a graduate student at the University of Idaho it may be reasonable to presume the bottles tested were from North America.
According to a google ad for www.specialchem4polymers.com there are 9 500 additives available for polymers.  The precise processes and formulas for manufacturing plastic products including food contact PET are often considered trade secrets and as such may be protected from disclosure by US law.
<==! Considering this situation it is hard to see how a well grounded claim could be made that DHEA which "is a common plasticizer that is used in many plastic items" is "not in PET".==>'''
-----End Moved Section------
Verifiability - The only scientific publication appears to be the Swiss Federal Laboratories report.  Do we have some direct references to Lilya Masters Thesis?  An abstract she presented appears at:  Society of Risk Analysis 2001 Meeting.  
However, it does not list the levels found.  Does anyone know what they were?  With the Swiss work indicating DEHA levels similar to background distilled water levels, it may be there is not much disagreement in the reports.
Suggested Content -  Let me suggest the following as a trial balloon for this section of the article:
===Health Concerns===
A Masters Thesis reporting that di(2-ethylhexyl)adipate could be detected in water from PET drinking bottles Society of Risk Analysis 2001 Meeting lead to concerns about the use and reuse of such bottles.  Subsequent work by the Swiss Federal Laboratories for Materials Testing and Research did not find levels at concentrations significantly above the background levels in distilled water Migration of organic components from polyethylene terephthalate (PET) bottles to water.
ChemGardener 17:58, 12 March 2006 (UTC)
thread_title:  Di(2-ethylhexyl)adipate Health Safety Concerns 

message: A Masters Thesis reporting that di(2-ethylhexyl)adipate could be detected in water from PET drinking bottles Society of Risk Analysis 2001 Meeting lead to concerns about the use and reuse of such bottles.  Subsequent work by the Swiss Federal Laboratories for Materials Testing and Research did not find levels at concentrations significantly above the background levels in distilled water Migration of organic components from polyethylene terephthalate (PET) bottles to water.
ChemGardener 17:58, 12 March 2006 (UTC)
thread_title: Health Concerns

message: Obviously there are a number of variations of the abbreviation. Where is the proper place to use each? (PET, PETE, PETP,PET-P)
*"PET" appears to be the industry abbreviation for Polyethlene (PE) Terephthalate (T)
*"PETE" appears to be the North American Resin identification code for recycling. There must be a historical fact about why PETE was chosen over PET? What countries use PET?
*"PETP" or "PET-P" appear to abbreviate Polyethylene Terephthalate Polyester, is this the proper abbreviation of the proper name?
When discussing the resin, what is the proper term to use?
I would recommend using the abbreviation "PET", as this term is used worldwide by all professionals dealing with polyethylene terephthalate. It is the official abbreviation according to an international ISO standard. (I don't know why the US uses the abbreviation "PETE" for identification in recycling operations. In the EU and in Japan, the marking for recycling is "PET".)
The abbreviation "PETP" (or its misspelling "PET-P") comes from the old German abbreviation, derived from Polyethylenterephthalat (=polyethylene terephthalate). This abbreviation was officially phased out in the mid 1980's, because it was felt that using a different abbreviation in German was confusing. However, old engineers in Germany still tend to use "PETP". Chemists don't anymore, as they are more familiar with chemical nomenclature.
Incidentally, up until the 1970s, the German abbreviation was "PÄTP" because the Germans used to use Ä instead of E for the "ethyl" group. I haven't seen "PÄTP" written in current documents for some while now and I presume that the usage of "PETP" will finally die out in the next decade or so, as the old guard retires.   Cynthia Bennett 17:22, 22 October 2006 (UTC)
thread_title: Abbreviation

message: The word Terylene is linked on this page, but when you click on the link you are sent straight back here. And there's very little information about Terylene to look at. —The preceding unsigned comment was added by 81.19.57.146 (talk) 14:20, 7 March 2007 (UTC)
replies: text: The redirect does work - Terylene is a PET fibre and fabric brand name. It might be a rather standard PET material, so maybe there's not much to say about it. --Evaa 14:25, 2 August 2011 (UTC)
replies: text: 'Terylene' was an ICI brand name for the fibre.  — Preceding unsigned comment added by 80.7.147.13 (talk) 10:56, 16 July 2012 (UTC)
thread_title:  Redirect doesn't work 

message: Could someone add info and links to the different types of PET? I work in thermoforming but I don`t know much about it other than how to work with it. The variants that I know of are:
*PET
*Colored PET
*PETG
*PETG 53
*COLORED PETG
*UTILITY GRADE PETG
*PETGag
*KPET
*aPET
*foamed PET
Thank you. Diggwadd (talk) 00:24, 19 October 2008 (UTC)
thread_title:  Variants 

message: Wouldn't the monomer of polyethylene terephthalate be ethylene terephthalate by definition? Where does bis-beta-hydroxyterephthlate come in?
Thanks
Mazari2 (talk) 05:47, 13 March 2010 (UTC)
thread_title:  Typo? 

message: This article seems to me typical of wikipedia. It is poorly written and poorly referenced. Of course, that's because it is mostly propaganda for the PET "recycling" industry. Take a look at the section on "recycling" if you don't believe this. It's virtually unreadable and totally unreferenced. In reality, little or no PET is recycled, but that's not what it says here. You get the impression that lots of PET is "recycled" but at most, a portion of it is sent through the production stream for a second time and *then* tossed into a landfill. That is NOT recycling. There simply is no cycle involved, unlike glass which is truly recyclable.
This article is genuinely scary because it is represented as fact, i.e. it's an encyclopaedic article. But like many articles on wikipedia, it serves mainly to further a particular group's own marginally criminal purpose--in this case misleading the public into thinking that PET is recyclable.  —Preceding unsigned comment added by 76.210.61.88 (talk) 18:57, 9 March 2011 (UTC)
replies: text: Can we start with kindly asking you to provide reliable references to your statements above (on PET). Materialscientist (talk) 00:56, 10 March 2011 (UTC)

text: Actually, about 60% of the total waste volume come from packaging, the majority of which is made from PET. According to this document, about 50% of all PET bottles on the market throughout the European Union in 2010 were recycled. In some countries (Switzerland for example), recollection rates even surpass 90%. I doubt that any other polymer material is recycled on a larger scale than PET. --Evaa 14:15, 2 August 2011 (UTC)
replies: text: True, some European countries are now collecting more than 90% of plastic bottles, however they are NOT recycling them, they are refilling them!   See the site  which will hopefully be incorporated soon into the article Reuse of water bottles -  Stillwaterising (talk) 09:20, 27 September 2012 (UTC)
thread_title:  THIS ARTICLE IS PROPAGANDA 

message: A discussion of manufacturing from plant material would be of interest.  Can this be applied to textile fibers, or only to packaging?  "PepsiCo Inc. unveiled a new bottle Tuesday made entirely of plant material that it says bests the technology of competitor Coca-Cola and reduces bottles' carbon footprint.  The bottle is made from switch grass, pine bark, corn husks and other materials. "  http://www.csmonitor.com/Business/Latest-News-Wires/2011/0315/Pepsi-bottles-no-more-plastic  — Preceding unsigned comment added by Billz2208 (talk • contribs) 16:48, 19 March 2011 (UTC)
thread_title:  Manufacturing from plant material 

message: This article does not mention the transparency (or otherwise) of PET to UV light, or the extent to which UV light may degrade the plastic.  I believe that this is an omission.   FreeFLow99FreeFlow99 (talk) 17:28, 8 May 2012 (UTC)
thread_title:  UV light 

message: Specific Heat is listed as 1.0 J/(g.K) - this does not agree with other sources which use 1.2 J/(g.K)  — Preceding unsigned comment added by 50.58.99.158 (talk) 20:52, 26 November 2013 (UTC)
thread_title:  Specific Heat 

message: I'm missing a chapter about chemical resistance. Which substances attack a PET container and which kind of substances can one safely contain in it? Is it not the main objective, to contain substances? --Manorainjan (talk) 14:23, 10 July 2016 (UTC)
thread_title:  Missing: Chemical resistance  

message: This link  (refers to: *Elman J.F., Greener J., Herzinger C.M., and Johs B. "Characterization of Biaxially-Stretched Plastic Films by Generalized Ellipsometry" Thin Solid Films 1998, 313/314, 814-818.) gives much higher n but it seems dated. Alliumnsk (talk) 15:47, 4 April 2017 (UTC)
thread_title:  Refraction index 

message: Under Uses:
[...] crystallizable PET or CPET tends to be black in colour
Yet under Physical properties:
[...] crystalline PET is opaque and white in most cases
The color of crystalline PET is also mentioned elsewhere, although not necessarily conflicting, including in Physical Properties and the introduction.  — Preceding unsigned comment added by 67.215.23.198 (talk) 14:50, 4 October 2017 (UTC)
thread_title:  Conflicting information on color of crystalline PET 

message: The article now mentions WATER bottles many times, but what about oil in PET bottles? For example MCT oil and hemp seed oil, that are sold at grocery stores and health food stores like iherb.
Are harmful things in PET bottles water soluble or fat soluble?
Wikipedia box on right-hand side now says: "Solubility in water: practically insoluble", but of course PET may have added chemicals thay may be soluble. What about solubility in diffrent kinds of oil?
Perhaps a good idea not to buy very many bottles at a time, as after several months or years something harmful will leach from PET bottle to oil? Does this happen at refridgerator temperatures, at about +4C or +40 Fahrenheit? Or only in room temperatures +20C-24C = +68-75F?
Antimony is not a problem:
http://www.tandfonline.com/doi/full/10.1080/19440049.2010.530296
"Exposure of the consumer by antimony migration from PET bottles into beverages and even into edible oils reaches approximately 1% of the current tolerable daily intake (TDI) established by World Health Organisation (WHO). 
ee1518 (talk) 13:46, 20 November 2017 (UTC)
thread_title:  Safety of food oil in PET bottles 

message: Dear contributors, just read this press release by Portsmouth Uni. It suggests that a bacterium has evolved that uses PET as food, and discusses a recent result on the improvement of the enzyme involved by the researchers. I don't feel I know enough to add this appropriately. For example, are the transesterification and esterification reactions mentioned as production techniques endothermic? Thehalfone (talk) 17:53, 17 April 2018 (UTC)
thread_title:  Plastic-eating enzyme 

message: Remove source number 37, as the domain is up for sale, and no longer seem relevant. Eliaskw (talk) 17:15, 28 June 2019 (UTC)
replies: text: .  -- Ed (Edgar181) 11:05, 29 June 2019 (UTC)
thread_title:  Semi-protected edit request on 28 June 2019 

message: The following Wikimedia Commons file used on this page has been nominated for deletion:
* 
Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 16:56, 6 December 2019 (UTC)
thread_title:  A Commons file used on this page has been nominated for deletion 

message: "Nevertheless, littering has become a prominent issue in public opinion, and PET bottles are a visible part of that."
Call it WP:BLUE but I feel this is claim is atleast decently large enough to require atleast one or two citations, both in regards to calling it a "prominent issue in public opinion" and that "PET bottles are a visible part of that"
Not particularly doubting the claims, however blue they may be, made here but atleast one citation would do this sentence good. 62.182.223.128 (talk) 08:43, 10 April 2024 (UTC)
thread_title:  Lack of citation in "Littering" section 

message: "Microplastics and NanoPlastics (MNPs) are emerging as a potential risk factor for cardiovascular disease in preclinical studies.
Polyethylene was detected in carotid artery plaque of 150 patients (58.4%), with a mean level of 21.7±24.5 μg per milligram of plaque.
Patients in whom MNPs were detected within the atheroma were at higher risk for a primary end-point event than those in whom these substances were not detected (hazard ratio, 4.53; 95% confidence interval, 2.00 to 10.27; P<0.001)".
... We don't know yet where this Polyethylene comes from. Eeaten/drinked, or inhaled. 
And is the risk because of plastic, or because people drink soft drinks which are not healthy.
176.72.38.245 (talk) 23:37, 21 May 2024 (UTC)
thread_title:  ALERT: Microplastics and Nanoplastics may cause increased risk of Cardiovascular Events!