[neptuneklm]

Hello, I am wondering if anyone can help me identify what TPE this is?  I'm pretty sure it's EPDM and something.  I am not sure what the doublet around 1750 is though.  The FTIR scan is attached.

[Arkcon]

Image may have been cut off, you may want to try attaching a normal image file, instead of waiting if people want to download a PDF.

[neptune]

I attached the file in a jpeg form, hopefully that works.

[Arkcon]

We generally don't refer to twin peaks in FTIR as a doublet.  Perhaps, you have two populations of C=O, one stronger and one weaker.  As per this reference: http://www2.ups.edu/faculty/hanson/Spectroscopy/IR/IRInterpretation.htm  Perhaps you can change the way you handle your sample to try and clean up the aromatic region around 1400?  As in, use a different solvent or prepare the solid sample more thinly.  Do you have a source for the spectra of your possible candidates?  As in, do these particular elastomers always give this sort of spectrum?

[Corribus]

It's difficult to take an IR spectrum and identify a precise chemical structure from it. You can do general functional group identification, but without a digitized spectral library at one's disposal (or personal experience with the exact molecule you've got there), it's kind of like finding a needle in a haystack.