[Igor Pietkov]

Hello,
I try to find solid material, that decompose to water and solid material (like sugar C₁₂H₂₂O₁₁) when this material is heated to a temperature 100-250°C (Any temperature from this interval).
Thanks in advance!

[Enthalpy]

Welcome, Igor!

What about a hygroscopic material, rather than a decomposition? Silica gel is dried in a kitchen oven, so 250°C isn't very far, and some material will fit. A polyol maybe, big enough to stay solid after absorbing water?

[Igor Pietkov]

Thank you!
Also according to wiki sugar also is hygroscopic material, so it's exactly what I was looking for (I have chosen Pentaerythritol). Actually I need this sort of material for fire extinguishing. I think if I can create cylinder made of such material, and inside this cylinder starts the fire, water vapor may block oxygen, so fire stops. Is this realistic?

[Enthalpy]

Two potential difficulties must be checked:
- Whether the amount of released water vapour suffices to extinguish the fire
- Whether the sugar itself burns. Sucrose for instance does, in the presence of ash.

What about a water gel? It contains mostly water, and heat could destroy a well chosen one, releasing the water. If destroyed under 100°C, the released liquid water may drop to the bottom and be less efficient, but if you find a gel destroyed above +100°C, it will release vapour.

As a child I had mixed sodium bicarbonate in epoxy to protect rocket walls from fire. It worked more or less: the released CO₂ visibly blew the flame away from the wall.

You could also use a foam inflated by a fire-extinguishing gas. The released amount is smaller, but some bromine-containing gases are efficient.