Talk:Silicone rubber

Comment

can silicone rubber,( tubing, plugs, caps,)be used in the electroplating industry. will it break down in plating tanks, or pretreatment tanks,( degreaser, hcl, cyanide, nitric, etc ).

• • Properties Section**

"However, typical medical products have failed because of poor design." This statement needs development and support.JascalX (talk) 06:13, 17 October 2009 (UTC)

Uncured silicone subjected to heat?

I have just learned recently that heat can destroy silicone caulks ability to cure. Storage above 80 F seems to be listed in various places but this seems too low. Has anyone experienced this?Longinus876 (talk) 19:47, 23 June 2012 (UTC)

I have seen problems associated with relatively longterm storage at elevated temperatures where the product actually starts to cure and becomes difficult or even impossible to dispense. It appears to be time AND temperature, as we corrected our situation by reducing time in storage (via a better FIFO procedure) rather than reducing the temperature of the warehouse. While not exactly "..destroy silicone caulks ability to cure", the results are similar in that once it begins to cure, it cannot be reformed into another shape. This inability to be reformed is likely what is being referenced as an inability to cure. Hope this helps. Ken (talk) 14:49, 11 March 2014 (UTC)

and further, the storage conditions I mentioned above were in a climate controlled factory which rarely if ever approached 80f. In this case it was more of the longterm storage than elevated temperature aspect. Either of these or a combination of them will caused curing to start, and once it starts it is difficult to work with. Other properties we noticed were that the product had poor adhesion, limited workability and poor mechanical strength (it cracked and split easily) even tho it would dispense. Ken (talk) 21:33, 14 May 2014 (UTC)

This discussion has been proceeding as if all silicone caulk cures using the same chemistry, which is unwise. For example, the well known GE Silicone caulks are marketed in groups I, II, and II-Plus or platinum. The GE Silicone I caulks are the type that exude acetic acid as they cure, while GE Silicone II is a neutral (catalyzed) cure, and the remaining are variations on the polymer and catalyst system (and whether its quartz (sand) filled to reduce cost). As I’ve experienced it, after excessive storage time unopened Silicone I caulk can fail to cure normally but my experience has been that if curing time is extended to as much as 5 days at 80°F even caulk that was 5 years beyond its use-by date cured. Silicone I caulk may be damaged if it’s frozen, I can’t say exactly how cold, -15°F wasn’t good for it, after thawing it comes out lumpy and didn’t cure overnight and it got scraped out so I couldn’t say if it would have eventually cured or not. I would expect that reason was that freezing caused the component materials to separate and weren’t available to each other to allow polymerization to proceed. Silicone II caulk seems to begin to cure in the tube when stored too long and comes out thick, dry or gritty. I tend to expect that up to some point elevated temperatures only accelerate the same behavior that takes longer at room temperature, I would also expect that there would be a temperature where an alternative reaction takes place altering the composition of the contents so that it can’t polymerize, it’s probably not far above the upper limit of the storage temperature range.PolychromePlatypus (talk) 13:39, 23 June 2020 (UTC)

Unclear Sentence

In a platinum-based silicone cure system, also called an addition system (because the key reaction building polymer is an "Addition reaction") — should it say "key reaction‐building‐polymer" or "key‐reaction building‐polymer" (or something else)?--Notveryactive89 (talk) 19:38, 16 August 2015 (UTC)

History without a date

>The first silicone elastomers were developed in the search for...
When?
> Resin-impregnated glass fibers were the state-of-the-art materials at the time.
When?
Dates accurate to within a few decades would be sufficient for me, e.g., "... in the first half of the 19th century..." Thanks, Nei1 (talk) 14:45, 29 March 2021 (UTC)

Errors in section "Production"

This section is badly garbled, both here and in the original source cited. The chemistry described is just plain wrong. I suggest deleting the entire section and relying on the more detailed descriptions of the polymerization processes given just above it. Methods for the preparation of elemental silicon, dichlorodimethylsilane, and polydimethylsiloxane are adequately described in their respective pages.

Swelling in nonpolar solvents

Silicone is unsuitable for use with unpolar solvents according to this table [1]. --Rainald62 (talk) 09:58, 29 September 2021 (UTC)

What is it made from?

The article doesn't seem to explain anywhere what materials silicone is made from, or how it's produced prior to the vulcanization process. 190.106.195.125 (talk) 17:56, 23 June 2024 (UTC)