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Are the thermal decomposition products of polyurea polymers known, especially of the urea group, in the absence of water?

Looking at the formula

R-NH-C=O
     |
    HN-R

there appears to be no obvious candidate for a decomposition product - not enough oxygen for CO2, not enough hydrogen for Ammonia.

Any ideas or, even better, references?

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Here's one abstract:

The primary fragmentation processes in the thermal decomposition of polymers were studied in detail on a series of structurally related polyureas by direct pyrolysis with a mass spectrometer. Our results indicate that polyureas I–III undergo a quantitative depolycondensation process analogous to that observed for N-monosubstituted polyurethanes. The thermal decomposition of polyureas IV–VI proceeds by intramolecular hydrogen transfer processes that occur at higher temperatures with respect to depolycondensation. Polycarboxypiperazine VI is decomposed by a single-stage decomposition mechanism that leads to fragments with amino end groups and carbon oxide.

I took a look at the article. Depolycondensation is accurate: most of the polyureas examined decomposed to the "parent" isocyanates and amines. The temperature range examined was 150°C to 350°C.

If you're interested in what happens at higher temperatures, I would guess a decomposition to mixtures of CO, ammonia, water, and possibly methane and/or hydrogen. But I didn't find any references that would support me after a quick look

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  • $\begingroup$ Thanks a lot, this was indeed the sort of answer I was looking for. $\endgroup$
    – xxyxyx
    Commented Mar 25, 2015 at 17:34

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