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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: Igor Pietkov on July 10, 2016, 12:20:14 PM

Title: Materials thermal decomposition
Post by: Igor Pietkov on July 10, 2016, 12:20:14 PM
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!
Title: Re: Materials thermal decomposition
Post by: Enthalpy on July 10, 2016, 08:04:17 PM
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?
Title: Re: Materials thermal decomposition
Post by: Igor Pietkov on July 11, 2016, 02:56:40 AM
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?
Title: Re: Materials thermal decomposition
Post by: Enthalpy on July 12, 2016, 05:41:59 AM
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.