How are amine filter beads manufactured?

[whatiam]

Hi, I have been reading about the regenerative carbon dioxide scrubbers used by the ISS and Shuttle. They involve filter beads coated with an amine chemical. The chemical temporarily binds to the CO2, and then the CO2 gets released when exposed to a vacuum.

https://www.nasa.gov/mission_pages/station/research/news/amine_swingbed.html

I have read these beads are porous or something. I am wondering how these beads are made. What kind of material makes the bead structure? What is the exact amine chemical being used? Any sources of information on this would be appreciated.

[Life_Support_32]

The exact process of making these beads and the chemical makeup is proprietary, but here is a paper on the Amine Swingbed payload that has some info in the background.

https://ttu-ir.tdl.org/handle/2346/59626

This payload has matured into the Thermal Amine Scrubber payload.

https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7404

https://ttu-ir.tdl.org/handle/2346/84942

[Remes]

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860021392.pdf
On Page 12 they talk about taking some plastics and carbonizing it with heat in an inert environment. Might be dated. Look for molecular sieve on ntrs.