Talk:Rubber

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There seems to be a great deal of stuff here that is overlapping with the latex page. There should be some better coordination between these two. Also it is worth noting that there are many types of rubber aside from Latex that are not addressed by this article. I almost think that a great deal of this content should be merged into the Latex page. Locke9k

The following was moved from the aricle page: olivier 04:48 Nov 27, 2002 (UTC)

Can anyone expand on this article? I wrote the very first bit, but I have no information on how synthetic rubber is produced! Mark Ryan

Can anyone please expand the uses section of this page?--Brijeshhsejirb 05:37, 5 November 2006 (UTC)

Synthetic Rubber is a big subject, covered by Polymer Science and Rubber Technology. I have added a note to that effect. G4sxe 18:45, 5 January 2006 (UTC)G4sxe

I have a half-memory that the seeds were initially smuggled out of Brazil, which, if true, would be the most profitable act of industrial espionage of all time... I need to check on this -- Malcolm Farmer

Henry Wickham gathered thousands of seeds from Brazil in 1876. They were germinated in Kew Gardens, England and the seedlings were sent to Colombo,Indonesia and Singapore. I will add this to the article. user:g4sxe

I am trying to understand why half of the world's rubber is produced synthetically. Is synthetic rubber cheaper or more expensive than natural one? Is it better or worse than natural one? Is not enough natural one produced in the world? AxelBoldt 10:43, 5 May 2004 (UTC)

Natural Rubber is best for low heat build up and is used in truck tire treads and the carcasses of both truck and car tires. Synthetic rubber is used for car tire treads, as much for wet grip as economy. user:g4sxe

I believe that for one thing synthetic rubber has reduced allergy potential due to the fact that allergic reaction to natural rubber is actually a reaction to certain non-rubber proteins produced by the plant. Unfortunately I can't remember my reference for this and therefore can't be sure it is accurate. user:locke9k

Contents

[edit] Edit

I moved the recent addition on Asian natural rubber to the previous paragraph, which deals with natural [rubber]. I removed the blight concern and link, because there is nothing remarkable that people might be concerned with a crop blight: this is true for any crop, and unless we go into it in some depth — which would be interesting — the squib of sentence was not useful. The link was to a syllabus; from long experience on my own website, syllabus pages very often disappear when the quarter or semester is over. — Bill 17:20, 15 Feb 2005 (UTC) Monkey D. Luffy is made of it.

[edit] Synthetic vs Natural

Synthetic rubbers have fundamentally different properties to natural rubbers and are therefore used for different purposes. For example, nitrile rubber has decreased permeability to many solvents and increased abrasion resistance.

I'd suggest the article needs an update as natural rubber and synthetic rubbers need to be more clearly delineated. Also a short monologue on chemical additives and potential allergies would be of use as they are of fundamental importance to a significant minority (natural rubber can cause a potentially fatal allergy).

I will try to address this in the coming weeks.

--John Spashett 09:29, 12 Jun 2005 (UTC)

Where can i found Kautschuk?

[edit] Kautschuk

C an you help me? I want to know something about Kautschuk.

The spelling is Caoutchouc. Caoutchouc is a vegetable gum produced by certain South American trees.

Caoutchouc was named rubber in 1770 by the English chemist Insert non-formatted text here, because it was used to rub out black lead marks. G4sxe 19:03, 5 January 2006 (UTC)G4sxe

[edit] India rubber

What is India rubber? It doesn't have an entry and could do with one. Cutler 08:06, July 30, 2005 (UTC)

India rubber comes from the India Rubber Tree, Ficus elastica. The milky sap or latex was once an important source of natural rubber, but it was of inferior quality.G4sxe 00:26, 6 January 2006 (UTC)g4sxe

[edit] Theory behind elasticity

Does anyone know exactly why rubber streches? what are the mechanics involved? i have heard two theories, and i was wondering which of them (if either) is true:

  • elasticity is caused by the bonds along the carbon backbone of a polymer bending back and form, with the bonds always reforming the prefered angle of 109°
  • carbon to carbon bonds stretching laterally, with the electrostatic attraction reasserting the original dimensions

i realise that they are both very similar, and in reality the reasoning is probably somewhere inbetween. could an expert please explain, and type it into the article? cheers, mastodon 20:50, 4 November 2005 (UTC)

Both theories are incorrect. The reason rubber stretches is mainly entropic (straightening of chains), not electrostatic (bending and stretching of bonds). See article. Klafubra 19:25, 6 May 2006 (UTC)

The section needs to be expanded to include disulfide bonds as well as glass transition temperature. Isopropyl 05:33, 22 May 2006 (UTC)

[edit] Why does the rubber erases the pencil?

Does anyone know exactly why rubber erases the pencil? what is the phenomenom? What are the forces involved?

[edit] Illustration

Someone should juxtapose a picture of a condom with that of the eraser. The subtitle, of course, would be "Rubber (American English)". I'd do it, but somehow it seems like I should first check to see if anyone thinks it to be too crude.

I'd like to see a mention, disamb or otherwise (at the top?) about condoms on here... Because if you were an ignorant HS student from a religiously intolerent state opposed to family planning (heh) you might've only heard the euphemism, and thus would be unable to find the information you were looking for.
I think a picture might be going over the top, however :)
~ender 2006-10-15 19:42:PM MST

[edit] Latex is an emulsion?

I'm certainly no expert on this, but isn't an emulsion a liquid suspended in a liquid? If referring to suspended rubber particles (as the entry does), surely colloid, or merely dispersion, would be a more accurate term?

I checked it out, and as I suspected, you are correct. (see http://www.britannica.com/ebc/article-9369794). I have updated the article. Verdatum 16:32, 4 October 2006 (UTC)

[edit] Latex Vs. Rubber

This article fails to explain how rubber differs from latex. On the contrary it insinuates they are one and the same. Is there a distinction? If not, shouldn't the two articles be merged?Verdatum 21:17, 3 October 2006 (UTC)

Alright, I'm in the process of editing the latex article to focus on the dictionary definition of a rubber polymer suspended in an aqueous solution. As such, latex is a raw material used to produce rubber. -Verdatum (talk) 18:15, 2 January 2008 (UTC)

[edit] Other uses/properties of rubber

Quite an interesting article so far but lots more could be added. For example: use of rubber in civil engineering (shock absorbers for bridges etc), vehicle tyres/tires (frictional properties especially when wet), deterioration with time and exposure to sunlight (?UV). Substitutes (especially electrical insulation used to be rubber but is now PVC, PTFE etc). How is it affected by temperature? ChrisAngove 17:08, 10 November 2006 (UTC)

[edit] Dry rot

Does anyone know exactly what happens to rubber that causes dry rot? That info would go well in this article and/or the dry rot article. -SCEhardT 04:52, 19 November 2006 (UTC)

[edit] Indian Rubber Board: why should it be here?

I fail to understand the rational behind having a separate section on "Indian Rubber Board" between the collection and chemical make up sections. Is it Vandalism? I am sure Malaysia and other big producers have similar authorities, shoule we talk about all of them? if we have to talk about indian rubber board should not this be part of the history section? Omar 18:47, 10 May 2007 (UTC)

[edit] Polyisoprene

The polyisoprene link points here, yet there is almost no discussion of synthetic polyisoprene. We need a separate entry on polyisoprene.

And agreeing with the comments above, there is little coordination between the rubber, elastomer, and latex pages.Delmlsfan 22:53, 3 October 2007 (UTC)

[edit] Recent news

Taken from http://technology.newscientist.com/article/dn13354

"Regular rubber gets its strength from the fact that long chains of polymer molecules are coupled, or "crosslinked," in three different ways: through covalent, ionic, and hydrogen bonding between molecules.

Of these three bond types, only the hydrogen bonds can be remade once a material is fractured, although normally there are not enough hydrogen bonds for the rubber to re-couple in this way."

Seems like a good explanation of the physical properties.


JD (talk) 15:00, 21 February 2008 (UTC)

[edit] Elasticity section

"This change in entropy can also be explained by the fact that a tight section of chain can fold in fewer ways (W) than a loose section of chain, at a given temperature (nb. entropy is defined as S=k*ln(W))"

This is the correct explanation not the stuff about conversion of the kinetic energy of the chains into heat energy which doesn't make sense as they're the same thing.

Additionally this section would possibly be better placed in elastomers as it applies to all elastomers not just rubber. 137.205.78.240 (talk) 11:45, 21 April 2008 (UTC)