Why does coloured plastic turn white when it's deformed or broken?

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paul.fr

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I have a lovelly collection on blue bic biros. When i bend or chew the pen lid, it changes from blue to white! Why is that?
« Last Edit: 05/03/2008 13:07:41 by paul.fr »

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Offline DoctorBeaver

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The polymers in the plastic stretch and change the refractive index.

(does that sound convincing?)  [:D]
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Offline chris

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Any consensus on this rather good question?

I'm bringing it back to the top for a second analysis by the physics gurus here!

Chris
I never forget a face, but in your case I'll make an exception - Groucho Marx

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Offline Bored chemist

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Lots and lots of very small cracks in the plastic scatter the light. Since these don't care much what wavelength the light is, the scattered light is white.
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Offline DoctorBeaver

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Isn't that what I said - but without the cracks?  [???]
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Offline Make it Lady

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No, you didn't say that small cracks are disinterested in light wavelength. I had some pupils that were exactly the same. I couldn't get them interested in light scattering.
Anyway as that question has been answered so quickly here is another one. When I put some plastic containers in the microwave why do they sometimes go orange?
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

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Offline DoctorBeaver

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So I neglected to mention polymer apathy. Sue me!  [::)]

Anyway as that question has been answered so quickly here is another one. When I put some plastic containers in the microwave why do they sometimes go orange?

The polymers in the plastic stretch and change the refractive index.

(does that sound convincing?)  [:D]
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Offline Bored chemist

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Do the plastic containers, by any chance, have food containing tomatoes in?
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Offline DoctorBeaver

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Or oranges? Tangerines? Apricots? Little orange aliens? A ginger wig?
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Offline Make it Lady

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Maybe bolognase sauce.

I seldom wash my Cilla wig in there. I am quite partial to having ginger hair. I used to have a Rita Furlough in the 80s.
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

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Offline DoctorBeaver

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Rita who?  [???]
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Offline Make it Lady

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That wasn't what I wrote I'm sure. My spell check has a mind of its own. That woman in the corner shop on coronation street. Yes I know its a soap (which us Brits use) but I haven't watched it since Stan died!!!
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

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Offline DoctorBeaver

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Stan who?  [???]
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