Polycarbonate visor material

[chemhero]

Hi everyone, I hope you are all well.

 

I have an idea for my final year chemistry project involving the surface modification of motorcycle helmet visor material; I understand that it is a polycarbonate of sorts, but how could I investigate what the repeat unit structure is? I need to find out before I start on the chemical modification

 

I guess an infra-red spectrum could yeild some information, but are there any other methods? What about some way to break down the polymer to its monomers, and then investigate that?

 

Matt

[YT2095]

IIRC DiphenylCarbonate (DPC) Is the monomer, I have some here, it`s really quite a Boring Crystaline chem, largely unreactive unless in a Basic soln.

 

so I`de recommend exploring DPC on its own rather than break down the polycarb itself (it takes Ages).

 

probably of no help at all, but maybe a pointer to cut some needless hard work out of it for you

[John Cuthber]

I think YT2095 is most of the way to the right answer. Almost all "polycarbonate" is bisphenol A polycarbonate. Comparison of the IR against a known sample is easy and (with the right kit) non destructive.

You can hydrolyse the stuff and get the monomer (well, I'm not sure about getting the CO2 part of it) but as YT2095 says it's slow. While this reaction is slow, it's quite fast enough to damage polycarbonate objects, in particular alkalies reduces the strength and, since polycarbonate is usually used where its strength is important, that's bad news. Pyrolysis would probably give fairly recognisable debris if you GCMS it. What sort of kit do you have access to?

[chemhero]

I did some more reading around, and also found that the polycarbonate is most likely to be based on bis-phenol. Given that, I'll test my visor against a sample and see how closley it matches to the known.

 

The more i think about this project of mine, the more excited I get.

 

Mmmmm chemistry

 

Matt