Talk:Plastic
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[edit] Older comments
The films link takes you to cinema 'film'. Dbroadwell 08:27, 24 Dec 2003 (UTC)
You're right -- "Film" points to an unrelated definition
Also, "British" is spelled with a capital 'B', when it should be lower, I believe.
- I don't think so - it's a nationality and all nationalities are initial caps - plenty of usage examples in Wikipedia and elsewhere. AncientBrit 17:45, 21 July 2006 (UTC)
Could somebody salvage the "sentence" in the top section that reads: "In the 19th century the discovered plastics based on chemically modified natural polymers: Charles Goodyear discovered vulcanization of rubber (1839) and Alexander Parkes discovered cellulose-based plastics in 1860ies."? Lomacar 04:35, 3 November 2005 (UTC) date/time
[edit] Polyvinyl butyral
There is a new article on Polyvinyl butyral (PVB). I would like to link it from here. Should it be under a "Common plastics" or "Special purpose plastics"? Thanks. --Edcolins 22:19, Aug 21, 2004 (UTC)
- It is my understanding that anything other than the commodity plastics such as PS, PP, PVC, PE, PC and ABS would be a specialty plastic. PVB is used only in a small niche market and I think its therefor safe to call it a specialty plastic. CoolMike 03:39, 12 Apr 2005 (UTC)
[edit] Bakelite
"Thermoplastics are tough and temperature resistant." - should that be "thermoset plastics" instead? Mr2001 12:06, 20 Sep 2004 (UTC)
- Righto, Done. Duk 16:09, 20 Sep 2004 (UTC)
[edit] Plastics Engineering
I added a link to the plastics engineering article I wrote in the 'see also' section. I'm enrolled in plastics engineering at UMass Lowell right now, but I'm still only in my 4th semester. Anybody care to help me be more specific on the definition of plastics engineering? I sorta just brainstormed up my own definition. Let me know what you think of the article please, its my first new article and I don't know if I've completed all the necesary steps to making a new article. CoolMike 20:41, 27 Feb 2005 (UTC)
[edit] Lead section needs to be more accessible to the general reader
Quick comment: this seems to be quite a thorough article, but I struggled to understand a lot of the lead section, particularly the third paragraph. It is, of course, appropriate to get technical in articles, but I would suggest that the lead section needs to be accessible to a general reader. Here's hoping someone can fix it ;-) — Matt Crypto 22:54, 11 Apr 2005 (UTC)
[edit] Structural formula
I think the polymers shown are not graphically accurate. Eg:
H H H H H H
\ / | | | |
C == C -> -- C -- C -- C -- C --
/ \ | | | |
H <bzr> H <bzr> H <bzr>
styrene monomer polystyrene polymer ("<bzr>" is a benzene ring)
The "polymer" shown is actually a repeating unit. To draw a structural formula of a polymer, you should include a -( )n- on the ends to show that it is a polymer. So it should look like :
/H H H H \
| | | | | |
----|- C -- C -- C -- C -|---
| | | | | |
\H <bzr> H <bzr>/ n
polystyrene polymer ("<bzr>" is a benzene ring)
[edit] Natural Gas vs. Petroleum
Although plastics are a by product of petroleum it is also very common, especially in the US, to use natural gas.
[edit] Structures
Instead of having "text images" of the chemical structures, I will try to draw up some in ChemSketch and put the images in instead. Give me a bit. --Shell 15:25, 31 December 2005 (UTC)
Tiny update: first one done: 
second: 
third: 
fourth: 
and lastly: 
I assumed the bonds without atoms were radicals.
[edit] Color
Color of polymer depends upon its cristallinity, fillers and chemical compositions. In anyway it does not belong to the Natural polymer section 23:27, 23 February 2006 (UTC)
[edit] Unchopped
I reverted a few steps back because one of the edits chopped off a good deal of the article. Would someone care to incorporate the lost changes after that? I'm on a bit of a time crunch. blahpers 12:27, 28 April 2006 (UTC)
[edit] Memory Plastic?
I've tried searching for info about memory plastic, but I've yet to come up with anything useful. Prehaps someone who knows about this could add this type of plastic under "special purpose plastics"?--137.186.211.84 04:18, 3 May 2006 (UTC)
[edit] inventor?
Who can be said to have "invented" plastic? Or is this article saying that rubber is a plastic, so it existed in mother nature before anybody tampered with the recipe and made human-made plastics? If so, who was the first to do the latter? I think we should give him or her credit.--Sonjaaa 19:38, 22 June 2006 (UTC)
I belive that the very first plastic was shown at the 1862 great international exabtion in london, by Alexander Parkes. Also Leo Baekalite invented, baekalite. --Robin63 18:47, 24 January 2007 (UTC)
[edit] Price and the future
The last para in this article contains much BS about nanocarbons that is of dubious relevance to the article. To tout them as cheaper than conventional plastics is just wrong. Diamond is not a plastic, and not an "alternative" Wikipedia is not a place to speculate about the future either. Graphene is no threat to plastics. There are no bowling balls made of nanocarbons. I am removing all this erroneous and speculative stuff from the article.DonSiano 15:09, 6 July 2006 (UTC)
[edit] Plastics vs Elastomers
The first two posts are from a discussion in the talk pages of User:Rifleman_82 and User:Hispalois. I've copied our discussion to here so that other contributors may participate in this discussion. Hopefully we can come up with more ideas and reach a consensus on how to classify polymers. --Rifleman 82 22:59, 24 July 2006 (UTC)
Hi. I noted your comment in your edit to Polybutadiene. Polybutadiene is definitely an elastomer or a rubber. It certainly does not resemble many of the other plastics listed. However, "plastic" is not well defined in the first place. A better term would be "polymer" but that wikipedia article does not focus on hydrocarbon based synthetic polymers. That said, how does polybutadiene not fit the definition of Plastic?
Plastic covers a range of synthetic or semisynthetic polymerization products. They are composed of organic condensation or addition polymers and may contain other substances to improve performance or economics. There are few natural polymers generally considered to be "plastics". Plastics can be formed into objects or films or fibers. Their name is derived from the fact that many are malleable, having the property of plasticity. Plastics are designed with immense variation in properties such as heat tolerance, hardness, resiliency and many others. Combined with this adaptability, the general uniformity of composition and light weight of plastics ensures their use in almost all industrial segments.
--Rifleman 82 14:48, 21 July 2006 (UTC)
Hi Rifleman. You raise a good point: what is the exact definition of plastic and why do elastomers not fit into it?
For me, the concept with physical reality is not "plastic" but "material with plastic behavior": a material that changes its shape under stress and retains the new shape; whereas a "material with elastic behavior" is one that changes its shape under stress and goes back to the original shape once the stress stops, dissipating energy in the process.
No material is purely plastic or purely elastic. Steel, for instance, behaves quite elastically for small deformations but is definitely plastic for big ones.
When people try to classify polymers, there are many possible ways to do it. One possibility is to look at the stress-deformation behavior of the material. This lets us differentiate between "plastic polymers" (i.e. plastics) and "elastic polymers" (i.e. elastomers). People also distinguish polymers that become liquid when heated and can be reshaped again ("thermoplastics") and those which simply decompose when heated ("thermosets").
In my opinion, these definitions are far from clear-cut and many ambiguities exist so we often have to refer to "usual practice". Polybutadiene, for instance, is an elastomer if it is properly vulcanized but if vulcanization goes too far it becomes hard and rigid, thus a plastic. In both cases it is a thermoset, i.e. it will decompose when heated. To complicate things even more, when it is not vulcanized at all we should rather look at polybutadiene as a liquid! So, how should we classify polybutadiene? The usual practice is to look at its behavior in its most widespread applications. For polybutadiene the main property of use is actually its elasticity and so it should be considered above all as an elastomer, a thermoset elastomer to be precise (there are thermoplastic elastomers, like SBS).
As you can see, there is a lot of work to do to properly define all these concepts in Wikipedia and then to set up categories so as to classify the different polymers in the most suitable ones. I have started that work in es: and if we ever find a consensus there I will propose the category structure for use in en:
--Hispalois 22:45, 24 July 2006 (UTC)
Thanks for your comments, which do help me understand your point of view. I do agree that the usual form of polybutadiene does not qualify as a "plastic" per se. It is hard to differentiate polymers as either "plastic" or "elastomer" and nothing in between. There certainly is a continuum and there really is no big difference in terms of synthesis, and modification of properties. Because of the great number of similarities other than the application, I fear we are introducing a false dichotomy. Should we expand the category further? "Polymer" will be the best category but it might be overly broad. --Rifleman 82 22:59, 24 July 2006 (UTC)
[edit] whats the difference
beetween thermosetting plastic and thermo plastics147.10.211.222 09:01, 15 August 2006 (UTC)tom
- See thermosetting plastic & thermoplastic. Femto 12:42, 27 August 2006 (UTC)
[edit] New method for making plastic
A new method for making plastic can be 100 times more efficient and can be used for more applications.[1]69.6.162.160 01:51, 10 October 2006 (UTC)Brian Pearson
[edit] Why so many quote marks?
It seems like every tenth word is in "quotes". It's kind of irritating to "read". 207.189.230.42 19:54, 22 November 2006 (UTC)
[edit] History of this page
The history of this page seems highly suspect, the majority of the content appeared in this revision: http://en.wikipedia.org/w/index.php?title=Plastics&oldid=43615 dated 3 April 2002.
The content is word for word identical to a series of pages from the packaging today website, one of which is http://www.packagingtoday.com/introplasticexplosion.htm. The wayback machine http://web.archive.org/web/*/http://www.packagingtoday.com/introplasticexplosion.htm has the first entry for this page as being 12 October 2002.
The packaging today website doesn't have any attribution to wikipedia and it's unclear where the content originated from, it does seem suspicious to have so much content appear at once and other edit's by the IP on that day specify that content was copied from a book http://en.wikipedia.org/w/index.php?title=Diving&oldid=83016. The history of the packaging today front page indicates that the content was added there between 5 April 2001 and 28 September 2002 http://web.archive.org/web/*sa_/http://www.packagingtoday.com/.
Can anyone shed any further light on who copied from who?
Lod 23:55, 19 December 2006 (UTC)
[edit] A plastics wikiproject
I am interested in making a place where people who desire to improve, update, or add information regarding plastics can communicate and collaborate. The reason I think this is necessary is becuase of a handful of flaws I see in the current organization of wikipedia plastics related articles. These flaws include:
- Trade name/common polymer material name/iupac name conflicts - see the articles on Nylon and Polyamide for a great example.
- Lack of detailed information on polymer processing techniques and related theory
- The over-emphasis of the resin identification code, which labels a huge number of common materials as "other"...Many products today simply have the polymer abreviation below the identification code, since it provides much more information. (ie. >SAN<...)
- The prevailence of misconseptions about the recycling of plastics, and/or their envirnmental impact. Some people (wikipedians included) seem to think of plastics as, "filling up our landfills". This is of course a rediculous assertion. These same editors fail to mention the weight reduction and related environmental benefits (lower transportation costs, etc.) that plastics products have over alternative materials. I have seen countless assertions that a certain plastic is "unrecycleable", a statement that can never be true of any material. Life cycle analysis type thinking needs to be employed, or at least mentioned in nearly every article which lists environmental concerns as a drawback of a material (plastic or otherwise). The list of these environmental/recycling misconseptions and misinformation is neverending.
- Polymers in medicine is a topic which can be greatly expanded.
I tried to see if there already was a plastics wikiproject, but I was unable to find one. Does anyone know how to start such a project or collaboration? Thanks for any and all comments, suggestions, or advice. I see all these problems and yet I can not fix them all as only one man, and I feel like we need a subject wide re-organization of our plastics related reference material. For now I guess I must be content with picking one article and concentrating on improving it... CoolMike 06:22, 21 December 2006 (UTC)
[edit] what's with the WARDY WAZ ERE :p?
I am not exactly sure what is up with the WARDY WAZ ERE :p section in this article. It appears to be somewhat new, and is somewhat.... annoying. Could someone please attempt to fix this up a bit? maybe change delete or add some things?
thanx --Robin63 18:47, 24 January 2007 (UTC)
Thank you --Robin63 06:06, 26 January 2007 (UTC)
[edit] can someone fix this?
the article is all weird at the top. i don't know how to fix it, but somewone who does know should.
Bear cube 22:02, 24 January 2007 (UTC)bear cube
- Done, see Help:Reverting on how to restore to an earlier un-vandalized version. Femto 10:40, 25 January 2007 (UTC)
[edit] Length
I do not feel strongly about this, however, I think that a lot of the sections in this article are a little too long. If someone knowledgeable was willing to devote some time and effort into slimming down some of the sections in this article, it would be gratefully appreciated. --Robin63 02:34, 12 February 2007 (UTC)
[edit] PVC
I didn't know PVC is used in salad dressing. No wonder I feel funny after eating that stuff. 03:36, 20 February 2007 (UTC)
[edit] Peak Oil
The last few paragraphs about price are very speculative. For one, they imply that reliance on alternatives to conventional crude oil would raise the market price; however, it is currently high demand that sets the market price for crude oil, not the production costs, which can be as much as 10 times lower for cheap Saudi oil and generally less than $20/barrel even for marginal plants. Consequently, I'm going to edit this to focus more on environmental concerns. 24.23.138.158 09:43, 10 March 2007 (UTC)
[edit] Adjective vs. noun
Is the word plastic not actually an adjective used to describe the properties of a polymer, vs. an actual noun? Granted, the word is misused widely in society, but when you have a "plastic polymer" the word plastic describes the polymer... there is no such thing as a "plastic". Perhaps it should be mentioned somewhere in the article that plastic is an adjective to describe a polymer displaying properties of plasticity, and not a substance of its own. 206.47.186.244 14:17, 19 March 2007 (UTC)
- See Wiktionary and http://dictionary.reference.com/browse/plastic. Looks like if it was considered a misuse at one point, it has entered accepted use now. -SCEhardT 16:35, 19 March 2007 (UTC)
