Talk:Siloxane

Etymology

Siloxane is defined by http://dictionary.reference.com/search?q=siloxane as "Any of a class of organic or inorganic chemical compounds of silicon, oxygen, and usually carbon and hydrogen, based on the structural unit R2SiO, where R is an alkyl group, usually methyl."

The wording of this article had stated that the etymology is a combination of silicon, oxygen, methane, but the true etymology is (according to the above and other definitions) silicon, oxygen, alkane where the alkyl group (alkane) involved is usually (but not always) methyl (ie, methan e). --Jared81 04:36, 27 September 2005 (UTC)

This article is defining polysiloxane not siloxane.

The OED states that siloxane is from the German siloxan, coined by Alfred Stock in 1917: Ber. d. Deut. Chem. Ges. (1917) 50, 170-182.

Ben (talk) 10:56, 24 February 2009 (UTC)

McDonalds

I don't know where somebody came up with putting siloxane in McDonalds food, it would be interesting if true but there needs to be a reference, I think it's BS.

• A siloxane-based polymer (dimethylpolysiloxane) is used as an anti-foaming agent in many commercially fried foods - see McDonald's List of Ingredients. -- MarcoTolo 21:18, 9 July 2007 (UTC)

Point of reference: the dimethylpolysiloxane is an antifoaming agent added to the vegetable oil that the particular food is cooked in. It should not be implied that the agent is directly added to the food, nor should it be implied that the food contains the substance in any considerable concentration (Are there quanitative tests to show that?). I would suggest that the statement should be changed to read "dimethylpolysiloxane is added to vegetable oil as an antifoaming agent. McDonalds uses this type of vegetable oil to cook certain products." Hokietiki@hotmail.com 18:17, 2 November 2007 (UTC) I performed the above edit and moved the McDonald's issue to the second paragraph that talks about polysiloxanes.Hokietiki@hotmail.com (talk) 20:07, 24 January 2008 (UTC)

Just a question. Why do they CARE about whether their oil foams a bit or not when they fry food? 74.36.97.127 (talk) 03:36, 8 June 2008 (UTC)

Silicone vs. siloxane

Should these two pages just merge? I'm not familiar enough with silicon chemistry to say if there's a subtle difference in common usage that's significant enough to justify separate pages, but the definitions seem to be the same.

Elmundomike 16:25, 17 November 2008 (UTC)

Siloxanes are a general class of compounds, of which the polymerized silicones are an example. I don't see a particularly pressing reason to merge them - did you have something particular in mind? -- MarcoTolo (talk) 16:30, 17 November 2008 (UTC)

cyclo siloxanes

Can anyone say if cyclotetrasiloxane,cyclopentasiloxane etc actually have H as the R groups, or are these just alternative names for dimethyl siloxanes ? - Rod57 (talk) 00:44, 24 August 2012 (UTC)

Merger proposal

I propose that silicones and siloxanes be merged. To my knowledge (which may be highly imperfect) they are basically the same thing. My greater concern is that while a handful of chemists might be able to distinguish these two, 99% of readers are likely to seek just general info on the such species. Such readers might be detered or confused by the presence of two articles on very similar species.--Smokefoot (talk) 00:36, 30 December 2012 (UTC)

This is a joke, right? You might as well try to merge polymerised isoprenes into "rubber", or eukaryotes into "animals", or polypropylene into polyethylene. What on Earth gave you the idea that they were the same, basically or otherwise? Anyway, it is not as though one of the articles were too small to stand on its own except as a stub. If you think that non-chemists couldn't stand the strain of two articles, then stick in a few links or "further reading" items, or ask a chemist to add some explanatory paragraphs. (Maybe a savvy non-chemist would be better of course, but at least then get a chemist to vet the result.) I am not personally shy of long articles, but I do require that they be thematically coherent. Are you suggesting that these two form a logical unit because of a conditionally relevant monomeric unit? That would be the nuttiest idea I have seen in yonks. If a layman wants to look up silicone (which well he might) it does not follow that he would have the slightest interest in siloxanes. What he would be looking up siloxanes for, I have difficulty imagining, but in case he should accidentally wander in, then I would be happy for him to find a hatnote or lede remark redirecting him to silicone. I strongly oppose the slightest idea of anything like a merge. It would neither structurally nor functionally be a bit of use and would reduce anyone not familiar with the subjects to wandering through a deeper mire than reading either subject alone. PS. I am no chemist, but it does not take a degree in chem to see that this would be totally unacceptable. If you feel strongly about it, consider an RFC, but it might make more sense first to rope in a tame chemist from Wikipedia:WikiProject Polymers and threaten him with non-chemists fusing the topics if they don't adjust it to your satisfaction. JonRichfield (talk) 13:34, 30 December 2012 (UTC)

Why all the sarcasm? I thought that we discussed ideas here rather than insult each other? What is the difference between silicone polymer and a siloxane polymer? That is the aspect that puzzled me. --Smokefoot (talk) 13:40, 30 December 2012 (UTC)

What did I say that struck you as sarcasm? I may have helicoptered a bit, because I was shaken, but that doesn't mean that I was poking fun at you; I was perfectly sincere. Sorry if you read it that way. To begin with, the concept of a "silicone polymer", though some people might use the term carelessly, is basically a confusion and not one in general use AFAIK; offhand I cannot remember having heard it. Silicones are a class, one class of several, of polymers of chemicals that contain the siloxane group. It is the siloxane that gets polymerised, not the silicone; the silicone is the product. Not every siloxane polymer is a silicone, just as not every polyolefin is polypropylene, though propylene (propene if you like) certainly is an olefin (or alkene). As an analogy, would you find it helpful if I compared such a fusion with uniting "forestry" and "carpentry" because they both deal in wood and are closely associated? The subjects are by no means irrelevant to each other, but they would make rotten bed-mates. Anyway, as I said, I could well imagine a layman wanting to know about silicones (he might be wanting to buy or use some), but if he wants to know about siloxanes, he had better be a budding chemist, or at least studying chemistry. Am I making sense? Pls say if not. And pls say if there are aspects of either article you would like me to assist with. JonRichfield (talk) 14:19, 30 December 2012 (UTC)

The articles are not entitled "Silicone polymers" and "Siloxane group". That would be a solution to the predicament I am trying to discuss. "Silicone polymers can be made from siloxane rings, but typically are not prepared that way", instead they are prepared my hydrolysis of diorganosilicon dichloride compounds, to my knowledge. Here are three sources on the relationship between the two topics:

• Ullmann's Encyclopedia of Industrial Chemistry "Silicones": "The term silicones ... each silicon atom bearing one or several organic groups... In industrially important silicones, these groups are usually methyl or phenyl. The silicones are known as polyorganosiloxanes"
• http://goldbook.iupac.org/S05671.html: "siloxanes: Saturated silicon-oxygen hydrides with unbranched or branched chains of alternating silicon and oxygen atoms (each silicon atom is separated from its nearest silicon neighbours by single oxygen atoms). The general structure of unbranched siloxanes is H3Si[OSiH2]nOSiH3. H3Si[OSiH2]nOSiH[OSiH2OSiH3]2 is an example of a branched siloxane. By extension hydrocarbyl derivatives are commonly included.See also: silicones"
• http://goldbook.iupac.org/S05670.html "silicones: Polymeric or oligomeric siloxanes, usually considered unbranched, of general formula [–OSiR2–]n (R ≠ H)."

We currently have a nice article on pdms, also known as polydimethylsiloxane. It is by far the most important silicone - or siloxane polymer. So lets keep the focus on the science.--Smokefoot (talk) 14:57, 30 December 2012 (UTC)

Hi Sf, you say inter alia:

"The articles are not entitled "Silicone polymers" and "Siloxane group". That would be a solution to the predicament I am trying to discuss..." It would be no solution to anything I can think of. For a start, to speak of "Silicone polymers" is about as meaningful as speaking of "siloxane polymer polymers", or polythene as polypolyethylene. I trust you agree that in the absence of particular and contrived contexts that is doubletalk in more than one sense. Hence: Silicone is a fair enough title. The siloxane article certainly has some text that needs attention, for example, "A siloxane is any chemical compound composed of units of the form R2SiO" should be something more like: "A siloxane is any chemical compound with the structure R2SiO..." I don't know who phrased the current wording, but it does not seem to have been a chemist.

"Silicone polymers can be made from siloxane rings, but typically are not prepared that way..." This is so irrelevant I can hardly express it. At a guess about half our polymers are not prepared from anything like their obvious monomers. Some of them could hardly be prepared that way at all, and many more it would not be convenient or economic to prepare that way. Would you try to prepare polycarbonates by polymerising carbonates? Or polyesters by reacting acids with alcohols? That would at least be possible, but... I am not sure what point you were making there.

You do have a point about the Siloxane article being somewhat opaque in its wording and not very coherent in its explanation. Also, in practice, though I know that we generally speak in singulars in naming articles, to call the article "Siloxane" suggests that it is about a compound called siloxane, whereas it is about classes of compounds and for practical purposes silane as the compound H2SiO does not exist, nor does Dimethyl silane. I think "Siloxanes", or better still "Siloxane chemistry" would be a better title. Are you looking at editing the article, or getting it renamed etc?

You say:"We currently have a nice article on pdms... So lets keep the focus on the science." Errr... OK I guess, but I fail to follow the line of thought.

Your references are OK of course, but what did you think they said that changed anything?

OK, where to from here? It is a tricky business. Much of the chemistry is specialist and takes a lot of 3D diagrams to represent it visually, so it is not easy to describe coherently and clearly. I think that your predecessors working on the articles took them on too lightly; Si chem is a blighter. Neither you nor I should make the same mistake. Doing a proper job is going to take someone a lot of work. JonRichfield (talk) 19:25, 30 December 2012 (UTC)

Image removal

Just to make sure it was intentional, User:Smokefoot removed this picture File:Boron Siloxane.JPG in the most recent set of edits, thus orphaning it. Not that it is a big deal, since it is on the commons.--Jorfer (talk) 20:51, 6 January 2013 (UTC)