Answer to yellowing from sci.polymers

[jeru...@amp.com]

As I mentioned in a previous thread I posted the yellowing plastic to
sci.polymers and got a few responses. Here is another one that I found
interesting:

>>>All plastics tend to discolor (yellow) with age. This is typical, and is
due to degradation (heat, light) of the polymer and/or oxidation of the
various components of the plastic part. Yellowing in dark storage could
also be due to a phenomenon known as "gas-fading" which is reaction of
nitrogen oxides (auto emmisions, etc.) with the polymer and the
antioxidants in the polymer. If the problem you are seeing is gas
fading,
then the parts should "bleach" back to their original color (or close to
it) with exposure to sunlight. If the color does not fade, then you are
dealing with the natural degradation of the polymer. Nothing you can do
(except maybe paint) will reverse the discoloration.<<<

So according to this account, the light we are hiding our toys from may
actually be the key to reversing some of the discoloation!
Interesting.
John

[Dan]

jeru...@amp.com wrote:

] >>>All plastics tend to discolor (yellow) with age. This is typical,

] and is
] due to degradation (heat, light) of the polymer and/or oxidation of
] the
] various components of the plastic part. Yellowing in dark storage
] could
] also be due to a phenomenon known as "gas-fading" which is reaction of
] nitrogen oxides (auto emmisions, etc.) with the polymer and the
] antioxidants in the polymer. If the problem you are seeing is gas
] fading,
] then the parts should "bleach" back to their original color (or close
] to
] it) with exposure to sunlight. If the color does not fade, then you
] are
] dealing with the natural degradation of the polymer. Nothing you can
] do
] (except maybe paint) will reverse the discoloration.<<<

I guess this is where all them yellow Devastator's are coming from,
then? :)

-D

[The_Great_Cornholio]

jeru...@amp.com wrote:
: As I mentioned in a previous thread I posted the yellowing plastic to

: sci.polymers and got a few responses. Here is another one that I found
: interesting:

[snip]
: So according to this account, the light we are hiding our toys from may

: actually be the key to reversing some of the discoloation!
: Interesting.
: John

I don't think I'd go sticking my TFs into sunlight and hope they get better.
IMHO, the gas reactions the guy was talking about aren't very likely : there
simply aren't enough auto emmisions in somebody's room to cause this. I
maintain that most yellowing is due to exposure to sunlight. (I know this
for a fact with Jetfire)

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[Rebecca Randolph]

The_Great_Cornholio wrote:
>
> jeru...@amp.com wrote:
> : As I mentioned in a previous thread I posted the yellowing plastic to
> : sci.polymers and got a few responses. Here is another one that I found
> : interesting:
> [snip]
> : So according to this account, the light we are hiding our toys from may
> : actually be the key to reversing some of the discoloation!
> : Interesting.
> : John
>
> I don't think I'd go sticking my TFs into sunlight and hope they get better.
> IMHO, the gas reactions the guy was talking about aren't very likely : there
> simply aren't enough auto emmisions in somebody's room to cause this. I
> maintain that most yellowing is due to exposure to sunlight. (I know this
> for a fact with Jetfire)
>

The yellowing effect can come from a variety of things and one is
indeed sunlight. The others are the chemicals and oils from your hands
and oxidation from the oxygen in the air. So it is definitely not a
good idea to put your Tfs in direct sunlight, but eventually they will
yellow if put away in the dark just not as quickly.

jeremy Randolph

n.W.o 4-life

Dennis Rodman is joining the n.W.o and will wrestle in a tag team match
with Hollywood this summer. HAHAHAHAHAHAHA!!!!!!

[Ivy Bohnlein]

Actually, this makes some sense to me. I remember being bummed when
I put Jetfire away because his head had yellowed in the sunlight, but
when I pulled him back out of the box, all of his plastic was yellow.
That means he yellowed *more* while he was in the dark. The question
is, is it just the oxidation, is it the sunlight, or maybe a combo
of both? Ie, he used to be in the sunlight and then was suddenly
wrenched out of it? Or maybe something to do with the newspapers
he was packed in -- newsprint fumes?

Well, he's out on the shelf now, so I will report if his yellowing
starts to fade back to white (pleasepleaseplease...)

Ivy
--
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