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General Science => General Science => Topic started by: paul.fr on 15/02/2008 22:29:50

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: paul.fr on 15/02/2008 22:29:50

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?

Title: Re: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 15/02/2008 22:31:03

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

(does that sound convincing?)  [:D]

Title: Re: Why does coloured plastic turn white when it's deformed or broken?
Post by: chris on 04/03/2008 23:44:05

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

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: Bored chemist on 05/03/2008 19:21:20

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.

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 05/03/2008 22:18:38

Isn't that what I said - but without the cracks?  [???]

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: Make it Lady on 06/03/2008 17:12:54

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?

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 06/03/2008 18:35:41

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

Quote from: Make it  Lady on 06/03/2008 17:12:54

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?

Quote from: DoctorBeaver on 15/02/2008 22:31:03

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

(does that sound convincing?)  [:D]

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: Bored chemist on 06/03/2008 18:56:55

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

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 06/03/2008 18:58:34

Or oranges? Tangerines? Apricots? Little orange aliens? A ginger wig?

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: Make it Lady on 06/03/2008 19:54:18

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.

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 06/03/2008 20:00:37

Rita who?  [???]

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: Make it Lady on 06/03/2008 20:30:48

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!!!

Title: Why does coloured plastic turn white when it's deformed or broken?
Post by: DoctorBeaver on 06/03/2008 22:37:07

Stan who?  [???]