Talk:Natural rubber/Archive 1

crap 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

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

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

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)

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

First of all, remember to sign your posts with four tildes (~~~~) so we know who you are. To answer your question, the reason rubber erases pencil is that the abrasives in the rubber eraser scratch the surface of the paper. This loosens some of the graphite particles, which lock onto the eraser. This is possible because of friction. TL The Legend (T) 18:08, 28 March 2019 (UTC)

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

192.119.154.251 (talk) 18:09, 14 April 2021 (UTC) Your religious prejudices are showing "ender" That type of entry is what causes people to dismiss Wiki. "Rubber" in that context is more a regional colloquialism exported to other areas as the US North East industrial areas population migrated across the country through the last half of the last century. A picture would be unnecessary. Disambiguation would put that entry under cultural references.

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)

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)

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)

It would be really interesting to have the Vapour Pressure of Natural Rubber added to the 'Properties' section.. Weldpurging (talk) 15:11, 15 July 2015 (UTC)

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)

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)

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)

This is a good point, particularly since this article was moved from 'rubber' to 'natural rubber' but I'm not sure there is enough content to require a separate article for polyisoprene. I'll add the content regarding polyisoprene here. -Verdatum (talk) 17:29, 17 October 2008 (UTC)

According to some sources, polyisoprene is natural rubber, but according to others, it's not latex. And then there's synthetic polyisoprene. I'm confused. Can someone clarify, either in this article, or in a separate? --HelgeStenstrom (talk) 08:50, 9 October 2010 (UTC)

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)

"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)

The introduction references the "entropy model of rubber", but never explains what it is. Fuzzform (talk) 07:29, 29 January 2009 (UTC)

gy55 is an example of natural rubber —Preceding unsigned comment added by 68.50.172.106 (talk) 23:39, 16 March 2009 (UTC)

The sentence: "The entropy model of rubber was developed in 1934 by Werner Kuhn" in the opening paragraph of the article feels tacked on to make someone sound important but is not relevant enough to need to be before the TOC. It should be moved down toward the entropy discussion later in the article. Recurve7 (talk) 20:13, 19 July 2009 (UTC)

Why does Caucho redirect here? The word does not appear in the article. Mathiastck (talk) 22:12, 20 November 2009 (UTC)

The term 'rubber woman' is related to this topic - maybe it deserves some coverage? (there's some disambiguation as well - e.g.: 'contortionist' and 'prosthetic woman') Actually is there any record of a model of a woman actually made from rubber (sort-of like a rubber water bag in shape of a woman - actually to be filled with water)? —Preceding unsigned comment added by 93.86.77.55 (talk) 16:27, 12 January 2010 (UTC)

I've never heard the term "rubber woman" used. It doesn't sound worth mentioning on an article related to the raw material. -Verdatum (talk) 16:53, 25 January 2010 (UTC)

Mayans are not pre-historical. They were not cave people. In fact, it wasn't the Mayans who created the rubber ball game, it was the Olmecs, a much older civilization in Mesoamerica. —Preceding unsigned comment added by 24.44.93.16 (talk) 07:21, 25 January 2010 (UTC)

Prehistoric means "prior to a system of writing". The fact uses the date of 1200 BC. The oldest dated evidence of Mayan writing is 400 BC. So yes, 1200 BC would be prehistoric. That being said, the fact is unsourced, and certainly questionable. If you have a source for the fact about the Olmec rubber ball game, then I'm totally in favor of replacing it. So where did you learn this? -Verdatum (talk) 17:05, 25 January 2010 (UTC)

actually the Cascajal block has been tentatively dated to between 1300 and 1000 BC, so 1200 BC, is likely not pre-historic. 71.161.209.199 (talk) 17:30, 18 February 2010 (UTC)

I just deleted the text:

The para rubber tree initially grew in South America, and the first European to return to Portugal from Brazil with samples of water-repellent rubberized cloth so shocked people that he was brought to court on the charge of witchcraft.

This seemed extremely improbable for several reasons, so I added a citation request in August 2009. After 8 months no evidence has been found to support it. Additionally, reading a different site suggests that the first person to introduce rubber to the Iberian Peninsula was Christopher Columbus, who was certainly not charged with witchcraft.

Having done that, reading of the azom.com history section suggests that our article is very incomplete on the history of rubber. "Discovery of commercial potential" sort of serves as a history section, but we do not mention the early Spanish-Mexican fabric waterproofing industry, development of rubber solvents and macintosh fabric, vulcanization, inflatable boats, the Stevenson Plan ... hardly anything actually.

I will try to add a bit when I get time, but I don't get much free time these days so I also encourage others to seek our referenced sources on the history of rubber! -- 202.63.39.58 (talk) 23:15, 13 March 2010 (UTC)

The following text has been moved from the article on Foam rubber, where it seemed out of place. Perhaps it can be worked into this article... Records trace back to as early as 500 B.C.E. During this period Mayans and Aztecs harvested this latex for waterproofing and formation of children’s toy spheres. Charles Goodyear invention of the vulcanization process for rubber in 1839 gave him the vision of a world filled with uses for this new durable elastic material. His ideas for chairs and mattresses made out of rubber were not seen until far after his death though.^[1] The first United States patent was issued in the early 1900s for synthetic rubber. AresLiam (talk) 03:12, 13 December 2013 (UTC)

Please stop direct this page to zh:橡膠. Natural rubber should direct to zh:天然橡膠. Thx, --RayYung (talk) 03:03, 16 June 2010 (UTC)

Correction: How do I stop bots from changing the wrong Interlanguage links? --RayYung (talk) 03:57, 16 June 2010 (UTC)

User:Sanoopj seems to be attempting some sort of vandalism from India. — Preceding unsigned comment added by 86.143.233.112 (talk) 12:02, 31 August 2012 (UTC)

Will this article eventually be edited to explain the etymology of the word "caoutchouc"? Jarble (talk) 00:48, 27 February 2013 (UTC)

The article states "is usual to tap a pannel at least twice, sometimes three times, during the tree's life" but the article gives no clue what a pannel is or what this means. I am unable to find any explanation of this on the web either, and the article doesn't seem to offer much context. — Preceding unsigned comment added by 75.151.101.218 (talk) 08:03, 11 March 2013 (UTC)

This section only discusses cultivation of Hevea brasiliensis, however rubber plantations composed of nothing but Parthenium argentatum or Taraxacum kok-saghyz also exist.^[2] These are btw noted as being much more environmentally friendly as they can be grown in locations where little else grows (ie steppes) rather than in rainforests.

Mention in article. 81.247.175.111 (talk) 11:28, 13 April 2013 (UTC)

The link for leaf blight led to the wrong pathogen--Phomopsis obscurans of strawberry. The South American leaf blight of rubber is Microcyclus ulei. (leaf blight is a general term for a type of symptom--many pathogens have such unhelpful common names). There is no Microcyclus ulei page yet, and I'm not up to creating one, so I removed the link. Lreuber (talk) 22:50, 22 May 2013 (UTC)