Yellowing cured!, (re)colour me amazed Options

[Bass X0]

Dumb Robot: You will doubtless seek life for your yellowed toys. But *AK* will they want life if -- if it comes like this? Hydrogen Peroxide affects no type of toy in the same way. What I ask -- -- will it do to Transformers?

Grimlock: Er... Make us whiter, make us brighter!

Dumb Robot: Ha-Ha *GGN* Yes, yes. It will do that all right. But what else? Will it eat you from the inside out? Will it distort your bodies? --Or will it make you crumble like my friends you encountered? Will your toys thank you for saving them -- or curse you? *UHH* Take me for example. I was suffering from a wasting disease, my color slowly decaying. It was long , drawn out but at least I'd reach the storage tub I so *URR* badly craved. Then they cured me. Only they DIDN'T cure me! Uh-uh! They brought me back to white so I could yellow again -- this time feeling every plastic part break down and fade. All thanks to Hydrogen Peroxide! It's said *UHN* we guard against the Hydrogen Peroxide jealously. Not so. We guard others AGAINST Hydrogen Peroxide!

This post has been edited by Bass X0: Dec 8 2008, 02:00 PM

[Autobus Prime]

Folks:

Warning! Science.

Warning 2! Amateur. (I'm trained as Wheeljack, not Quickmix.)

You have been warned. Now prepare for the geekstorm.

WHOA.

This is awesome to the max. UV-catalyzed peroxide bleaching! Now we need to figure out what's happening.

I think I've got a partial theory.

Photooxidation creates chains of alternating single-double carbon bonds in the hydrocarbon molecules - the conjugated unsaturation mentioned in the NES article below. This forms chromophores in the molecules, color-causing regions, turning the molecules into dyes. Chromophores formed by conjugated systems...are yellow!

The hydrogen peroxide bleaches these by breaking double bonds and forming an epoxide group - an oxygen atom bonded to two adjacent carbons, which remain bonded to each other by a single bond. This turns the chromophores colorless.

Now, here's what I'm wondering -

-where in the ABS structure is the chromophore forming? The polybutadiene chain or the cross-chains?

-brittleness (due to UV-induced cross-linking) and yellowing seem to be separate modes of deterioration. What effect might this relatively fast UV-catalyzed oxidation have on cross-linking?

-how does the UV light catalyze this bleaching, if indeed it is doing that?

There's a LOT of papers on photooxidation and photodegradation of polymers! I have been browsing abstracts, because I don't want to buy the actual papers. If anybody has access to polymer science journals, it would be well worth a look. I think there is a neat puzzle here for the chemists here to figure out! I know you're out there.

One thing I can suggest from an engineering POV is a test for brittleness. Take some identical parts and treat them, then do a tension test to see how easily they break, and examine the broken ends for signs of embrittlement. Compare yellowed parts, bleached yellowed parts, and unbleached, unyellowed parts. I think a good source would be a scrap computer case; they're flat, so you could get good test specimens, and they're usually ABS.

Nerdy excitement! Let it spill into the streets.

Refs:

http://www.vintagecomputing.com/index.php/archives/189

http://en.wikipedia.org/wiki/Conjugated_system

http://en.wikipedia.org/wiki/Chromophore

http://mysite.du.edu/~jcalvert/phys/perox.htm

This post has been edited by Autobus Prime: Dec 8 2008, 12:58 PM

[G.B.Blackrock]

You will doubtless seek life for your yellowed toys. But *AK* will they want life if -- if it comes like this? Hydrogen Peroxide affects no type of toy in the same way. What I ask -- -- will it do to Transformers?

Er... Make us whiter, make us brighter!

Ha-Ha *GGN* Yes, yes. It will do that all right. But what else? Will it eat you from the inside out? Will it distort your bodies? --Or will it make you crumble like my friends you encountered? Will your toys thank you for saving them -- or curse you?

Bass X0 wins the thread!

[Treadshot 2.0]

This should be frontpaged. It's some of the biggest news in toy collecting fandom.

[G.B.Blackrock]

This should be frontpaged. It's some of the biggest news in toy collecting fandom.

Would need some heavy "we're still trying to determine if this method is safe" disclaimers....

[lonegamer8]

This should be frontpaged. It's some of the biggest news in toy collecting fandom.

Would need some heavy "we're still trying to determine if this method is safe" disclaimers....

Too true.

[Esser-Z]

I'll be watching this. Mostly with my science nerd side, for now (don't have any yellowed toys, yet). It's tentatively really cool.

[Spark]

Hmm... I've got an Ultra Magnus and a bunch of Seacons and Micromasters that need this, but I do think we need some time trials before this becomes the standard.

I feel like we're being the toy version of the FDA.

[Fender Bender]

Hmm... I've got an Ultra Magnus and a bunch of Seacons and Micromasters that need this, but I do think we need some time trials before this becomes the standard.

I feel like we're being the toy version of the FDA.

Well, we are so to speak. We are all AFRAID (Action Figure Research And Improvement Developers)













(IMG:style_emoticons/default/icon-waspy.gif)

[Cat]

So, I just got back from the dentists.

I got my teeth whitened. They used some new light procedure, cost a grand.

BUT I have a little kit, so I can periodically top my teeth off as needed. At the moment, they're now dazzling white.

I'm curious about what effect, if any, this gel would have on a TF.

Thoughts?

[Tigerpaw28]

So, I just got back from the dentists.

I got my teeth whitened. They used some new light procedure, cost a grand.

BUT I have a little kit, so I can periodically top my teeth off as needed. At the moment, they're now dazzling white.

I'm curious about what effect, if any, this gel would have on a TF.

Thoughts?

I think you just hit the nail on the head. If I'm not mistaken, that gel contains hydrogen peroxide and as you said, it's being activated by the light.

That's pretty similar to the process that's the subject of this thread. This would be a good starting point to find out what, exactly, is happening to the plastic. Which is what I will do tomorrow.

This post has been edited by Tigerpaw28: Dec 9 2008, 01:42 AM

[Bass X0]

I got my teeth whitened. They used some new light procedure, cost a grand.

was it worth it?

white teeth is something desirable but a grand goes a long way spent on other stuff.

[Cat]

I got my teeth whitened. They used some new light procedure, cost a grand.

was it worth it?

white teeth is something desirable but a grand goes a long way spent on other stuff.

Yes, it was worth it. I'm in agony because it's aggravated the nerve endings in my teeth, but I'm absolutely thrilled with the results.


If it helps find a cure for (solemn voice) TF yellowing, then no price was too high........

[Silent_Magnus]

I wonder if this video is appropriate for this topic.

link

(if you want to, you can see Darth Vader as a yellowed toy, and the fire as Hydrogen Peroxide)

This post has been edited by Silent_Magnus: Dec 9 2008, 08:15 AM

[Domon Kasshu]

I saw this story on the front page, so I thought I might share a few images of using hydrogen peroxide on a Transformer as well.

This is the original knee joint on a Smokescreen Alternator: Original Knee Assembly

The joint was treated with overrun of store bought hydrogen peroxide from a q-tip over the course of a few days(it was actually being used to remove the racing detail on the car), without being placed in sunlight for extended periods of time.

Picture One
Picture Two
Picture Three

The leg pretty much crumbled in my hands when I was trying to work with it later. I'd especially be cautious with thin plastic and areas where joints are moved frequently... but I can't say I'd recommend doing this at all.

[Autobus Prime]

Folks:

I feel I should also point this out...and I think there ought to be more emphasis on safety in the news article. A nice white Fort Max does you no good if you can't see it.

MSDS for H202, 20% - 40%:

http://msds.fmc.com/msds/100000010225-MSDS_US-E.pdf

Please take note that these concentrations of hydrogen peroxide...

-Are corrosive to eyes, nose, throat, lungs, and GI tract,

-May cause corneal damage or blindness if splashed in eyes, especially if not rinsed away,

-Reacts quickly with wool, cotton, and leather - do not wear these materials when working with these concentrations of H2O2,

-May generate large amounts of gas

-May concentrate by water evaporation and self-ignite if spilled on combustible materials and allowed to dry. Combustible materials exposed to hydrogen peroxide should be submerged or rinsed with lots of water to ensure all peroxide residue has been removed.

This is not the fizzy 3% stuff from the drugstore!

DK: That's interesting. It almost looks like a GPS break in the photo - is it similar? Brittle fracture, dust and shards?

What concentration were you using and how long did it remain on the parts? Anybody know if that's PVC or ABS?

[Galenraff]

This sounds interesting, but I hope it's not the new "dishwasher dusting."

[JRSBill]

We use 35% here at the shop for doing various cleanings.

If you don't wear gloves and get it on yours hands, they will instantly turn white and BURN. That's not even if it gets in a cut, then it is even worse.

As for brittleness, SCH80 PVC pipe is grey and it will completely remove the color from it. After a few years of using liquid with the H202, the SCH80 pipe does become brittle and can shatter.

Toys are probably around SCH1. If it weakens SCH80 piping after a few years, I can only imagine what will happen to toys.

G1 stuff might hold up better than the newer stuff. I'm sure Animated Ratchet soaked in that stuff would just fall apart if left exposed to the stuff too long.

[Autobus Prime]

We use 35% here at the shop for doing various cleanings.

If you don't wear gloves and get it on yours hands, they will instantly turn white and BURN. That's not even if it gets in a cut, then it is even worse.

As for brittleness, SCH80 PVC pipe is grey and it will completely remove the color from it. After a few years of using liquid with the H202, the SCH80 pipe does become brittle and can shatter.

Toys are probably around SCH1. If it weakens SCH80 piping after a few years, I can only imagine what will happen to toys.

G1 stuff might hold up better than the newer stuff. I'm sure Animated Ratchet soaked in that stuff would just fall apart if left exposed to the stuff too long.

JB:

Schedule 80 is actually a dimensional schedule (wall thickness etc) rather than a material spec...it's thicker than Sch 40, but the resin et cetera isn't necessarily better.

The point about safety is REALLY good and needs to be repeated, or sooner or later somebody is going to hurt themselves.

I am wondering now whether PVC itself is more prone to damage than ABS. Is this pipe in contact with H202 flows continuously for several years, or is it being used to clean the pipes? How often?

[Cat]

The stuff I got for my teeth is 22%.

That seems like a reasonable concentration to experiment with.

Now I just need to buy a junker off Ebay, I don't have anyone I'm willing to sacrfice...