Talk:Photodegradation - Revision history

ShootingStar7X: /* Recent occurrences on the wrong page? */ new section

2023-05-04T01:25:41Z

Recent occurrences on the wrong page?: new section

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	== Possible causes ==		== Possible causes ==
	This may not be true of all cases, but there is a known cause for yellowing in some plastics. In particular, bromine is what made the SNES prone to yellowing. Some types of plastic yellow as a simple result of UV exposure. These tend to stay on the pale side and can look spotty depending on exposure. Brominated plastics, however, are a result of the fire retardant chemical added to them not being held en matrix properly and migrating to the surface of the plastic. In the case of brominated plastics, they can yellow even if they aren't exposed to UV light. They tend to be more of a yellowish brown. This is what happened with the SNES, in fact. --[[User:King Starscream\|King Starscream]] ([[User talk:King Starscream\|talk]]) 14:47, 22 December 2015 (EST)		This may not be true of all cases, but there is a known cause for yellowing in some plastics. In particular, bromine is what made the SNES prone to yellowing. Some types of plastic yellow as a simple result of UV exposure. These tend to stay on the pale side and can look spotty depending on exposure. Brominated plastics, however, are a result of the fire retardant chemical added to them not being held en matrix properly and migrating to the surface of the plastic. In the case of brominated plastics, they can yellow even if they aren't exposed to UV light. They tend to be more of a yellowish brown. This is what happened with the SNES, in fact. --[[User:King Starscream\|King Starscream]] ([[User talk:King Starscream\|talk]]) 14:47, 22 December 2015 (EST)

			== Recent occurrences on the wrong page? ==

			Does anyone else think we should move the [[unpaintable plastic]]'s section on recent occurrences of photodegradation here, and vise versa? I think it's weird that the page covering the phenomenon in more detail is the one ''not'' primarily about said phenomenon. [[User:ShootingStar7X\|ShootingStar7X]] ([[User talk:ShootingStar7X\|talk]]) 21:25, 3 May 2023 (EDT)

King Starscream at 19:47, 22 December 2015

2015-12-22T19:47:11Z

← Older revision		Revision as of 19:47, 22 December 2015
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	My six inch Titanium Ultra Magnus has visible discolouration. Some spots even have visible lines between discoloured and non-yellowed plastic. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)		My six inch Titanium Ultra Magnus has visible discolouration. Some spots even have visible lines between discoloured and non-yellowed plastic. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)
	: A more recent example would be BotCon Gigatron, who some report has some yellowing parts. But I'm not sure we need additional examples. --[[User:ItsWalky\|ItsWalky]] ([[User talk:ItsWalky\|talk]]) 03:29, 30 August 2014 (EDT)		: A more recent example would be BotCon Gigatron, who some report has some yellowing parts. But I'm not sure we need additional examples. --[[User:ItsWalky\|ItsWalky]] ([[User talk:ItsWalky\|talk]]) 03:29, 30 August 2014 (EDT)

			== Possible causes ==
			This may not be true of all cases, but there is a known cause for yellowing in some plastics. In particular, bromine is what made the SNES prone to yellowing. Some types of plastic yellow as a simple result of UV exposure. These tend to stay on the pale side and can look spotty depending on exposure. Brominated plastics, however, are a result of the fire retardant chemical added to them not being held en matrix properly and migrating to the surface of the plastic. In the case of brominated plastics, they can yellow even if they aren't exposed to UV light. They tend to be more of a yellowish brown. This is what happened with the SNES, in fact. --[[User:King Starscream\|King Starscream]] ([[User talk:King Starscream\|talk]]) 14:47, 22 December 2015 (EST)

ItsWalky: /* Modern examples */

2014-08-30T07:29:46Z

Modern examples

← Older revision		Revision as of 07:29, 30 August 2014
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	My six inch Titanium Ultra Magnus has visible discolouration. Some spots even have visible lines between discoloured and non-yellowed plastic. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)		My six inch Titanium Ultra Magnus has visible discolouration. Some spots even have visible lines between discoloured and non-yellowed plastic. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)
			: A more recent example would be BotCon Gigatron, who some report has some yellowing parts. But I'm not sure we need additional examples. --[[User:ItsWalky\|ItsWalky]] ([[User talk:ItsWalky\|talk]]) 03:29, 30 August 2014 (EDT)

Takeshi357 at 07:05, 30 August 2014

2014-08-30T07:05:54Z

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	:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)		:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)
	::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)		::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)
	:::I'm not so sure about that explanation, Nevermore. It doesn't take much etching for its effects to become visible, and the gloss would certainly change, but the treated plastic I've seen in pictures remains glossy and unchanged except for color.		:::I'm not so sure about that explanation, Nevermore. It doesn't take much etching for its effects to become visible, and the gloss would certainly change, but the treated plastic I've seen in pictures remains glossy and unchanged except for color.
			::::Isn't there some kind of material you can layer the surface with after the peroxide treatment that protects it from UV light? And if the discolouration is caused by factors other than light, it might actually just be better to paint it over. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)

	I got a different one from Dr. Rudy Deanin, remember:		I got a different one from Dr. Rudy Deanin, remember:
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	Anyone willing to go through, examine and evaluate the [http://www.tfw2005.com/boards/transformers-toy-discussion/197984-yellowing-problems-might-help-25.html more recent] first-hand reports on the peroxide treatment?--[[User:Nevermore\|Nevermore]] 09:06, 22 April 2011 (EDT)		Anyone willing to go through, examine and evaluate the [http://www.tfw2005.com/boards/transformers-toy-discussion/197984-yellowing-problems-might-help-25.html more recent] first-hand reports on the peroxide treatment?--[[User:Nevermore\|Nevermore]] 09:06, 22 April 2011 (EDT)

			== Modern examples ==

			My six inch Titanium Ultra Magnus has visible discolouration. Some spots even have visible lines between discoloured and non-yellowed plastic. [[User:Takeshi357\|Takeshi357]] ([[User talk:Takeshi357\|talk]]) 03:05, 30 August 2014 (EDT)

Nevermore: /* Updates */ new section

2011-04-22T13:06:47Z

Updates: new section

← Older revision		Revision as of 13:06, 22 April 2011
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	-It's possible that the use of H2O2 could cause crosslinking...would be interesting to compare the probabilities of the different reactions. I should go ask my chem engineer buddies... --[[User:Autobus Prime\|Autobus Prime]] 13:31, 9 July 2010 (EDT)		-It's possible that the use of H2O2 could cause crosslinking...would be interesting to compare the probabilities of the different reactions. I should go ask my chem engineer buddies... --[[User:Autobus Prime\|Autobus Prime]] 13:31, 9 July 2010 (EDT)

			== Updates ==

			Anyone willing to go through, examine and evaluate the [http://www.tfw2005.com/boards/transformers-toy-discussion/197984-yellowing-problems-might-help-25.html more recent] first-hand reports on the peroxide treatment?--[[User:Nevermore\|Nevermore]] 09:06, 22 April 2011 (EDT)

Autobus Prime: /* I asked a chemist... */

2010-07-09T17:31:19Z

I asked a chemist...

← Older revision		Revision as of 17:31, 9 July 2010
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	Rudy Deanin		Rudy Deanin

	-It's possible that the use of H2O2 could cause crosslinking...would be interesting to compare the probabilities of the different reactions. I should go ask my chem engineer buddies...		-It's possible that the use of H2O2 could cause crosslinking...would be interesting to compare the probabilities of the different reactions. I should go ask my chem engineer buddies... --[[User:Autobus Prime\|Autobus Prime]] 13:31, 9 July 2010 (EDT)

Autobus Prime: /* I asked a chemist... */

2010-07-09T17:31:00Z

I asked a chemist...

← Older revision		Revision as of 17:31, 9 July 2010
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	Rudy Deanin		Rudy Deanin

			-It's possible that the use of H2O2 could cause crosslinking...would be interesting to compare the probabilities of the different reactions. I should go ask my chem engineer buddies...

Autobus Prime: /* I asked a chemist... */

2010-07-09T17:25:16Z

I asked a chemist...

← Older revision		Revision as of 17:25, 9 July 2010
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	:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)		:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)
	::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)		::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)
			:::I'm not so sure about that explanation, Nevermore. It doesn't take much etching for its effects to become visible, and the gloss would certainly change, but the treated plastic I've seen in pictures remains glossy and unchanged except for color.

			I got a different one from Dr. Rudy Deanin, remember:

			(From the Allspark)

			QUOTE(Dr. Rudy Deanin)
			In answer to your December 8 inquiry, the 3 monomer units of ABS all contain somewhat unstable atoms or groups which are activated by UV + atmospheric oxygen (photooxidation). They all contain double or triple bonds, which absorb UV. When one C=C bond absorbs light, it is only in the far UV, so we don't see it. It activates an adjacent group and forms another (conjugated) C=C group. This C=C-C=C (allylic) group is more active, so it forms a third, and so on. As this conjugated (-C=C-) chain grows longer, it absorbs longer and longer wavelengths. When it is about 6 C=C groups in a row, it reaches the wavelength of visible light, and we see the degradation. As it grows till longer, it absorbs mores and more visible light, and the color grows darker and darker. The reason peroxide and sunlight cause bleaching is that they destroy a C=C bond and break the conjugated chain.

			Embrittlement is caused by crosslinking. When UV and/or oxygen attack an unstable -C:H bond, they split it into -C. and .H radicals. When 2 adjacent polymer molecules have -C. radicals, they pair and form a -C:C- crosslink.

			That's my simple-minded explanation. If you read very far into the literature, they get much more complicated, sometimes even contradictory.

			Rudy Deanin

Nevermore at 09:33, 21 April 2010

2010-04-21T09:33:46Z

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	...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)		...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)
	:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)		:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)
			::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)

Detour at 13:24, 20 April 2010

2010-04-20T13:24:00Z

← Older revision		Revision as of 13:24, 20 April 2010
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	...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)		...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)
			:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)

← Older revision		Revision as of 09:33, 21 April 2010
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	...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)		...And he told me that the hydrogen peroxide basically destroys the sun-damaged top layer of the plastic, thereby revealing the correctly-colored layer below. Thus, this treatment isn't infinitely reproducable.--[[User:Nevermore\|Nevermore]] 08:31, 20 April 2010 (EDT)
	:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)		:...without damaging the paint? --[[User:Detour\|Detour]] 09:24, 20 April 2010 (EDT)
			::It basically destroys a layer of the plastic. If the same problem occurs again, and you repeat the process, another layer is destroyed. If you repeat that often enough, there will be no plastic left.--[[User:Nevermore\|Nevermore]] 05:33, 21 April 2010 (EDT)