Are there any Pyro-GC experts out there?

I recently aquired a pyrolysis sampling unit from another location in our company and have been putting it to use identifying polymer and rubber samples. I'm new to pyro sampling,but am trying to learn.

I have been asked to identify a piece of foam rubber insulation, it appears to neoprene rubber, however the pyro chromatogram does not match with the pyrogram obtained for known sample of neoprene under identical conditions, (Pyro-600C, chromatograph Rtx-5 50 - 300C).

When I pyrolyze the known neoprene, I see a lot of chloroprene monomer, isoprene, chlorobenzene and some other chlorinated unsaturated cyclic compounds.

When I pyrolize the unknown, I see phenol, toluenthiol, Indene, benzene, toluene and some branched aliphatics. I can't seem to find any monomer which makes sense.

Any suggestions would be greatly appreciated.

Thanks,

Mike

Hello,

we have some experience with Agilent GCMS and injections of glue and others. But we made an extra - a direct injection in the MS without using the GC-column. If it is interesting for You, contact me.

Try contacting the manufacturer of your pyrolysis unit. They probably will be able to help you with this. If you have a CDS unit they have extensive experience with pyrolysis and have produced many chromatograms and applications for this. There are also some good books on pyrolysis that you probably should get if you will have to do this on a routine basis.

could the unknown not be neoprene? are you able to take an IR of the unknown to verify it's neoprene?

Polystyrene can make some of those pyrolyzates listed for your unknown, although usually I see monostyrene and methylstyrenes as well, but under different conditions.

Calling the manufacturer of the pyrolysis unit is good advice.