CNT fibers and films can withstand very high temperatures but with a few limitations depending on the application
For our CNT materials, we can safely say they can withstand temperatures up to 500c when in an oxygen environment. The maximum temperature is also dependant on how much time it is exposed to that elevated temperature.
For an oxygen-free environment, the materials can withstand temperatures over 1000C.
however, we do not have ideal data for temperatures over 1000c at this time.
The synthesis temperature of the CNTs is just over 1000 C so it is unlikely to withstand temperatures much above 1000 C even in an oxygen-free environment. That said, it is unlikely that our fibers would survive temperatures over 1500 C.