Best material for reusable motor casing?

[Interstellar]

I've been making rocket fuel from homemade ingredients, which works great, but with all exothermic reactions, it releases a LOT of heat. I am looking for a material that I can reuse more than twice, can withstand prolonged exposure to extreme heat, and weigh less than 2.00g/cm^3. I've tried carbon fiber tubes, but the binder glue that holds the fibers in their shape will vaporize when it gets hot so when the test is over, I'm left with a pile of loose fibers.

 

[ksaves2]

Formulas are generally reserved for the Research forum so a moderator might intervene here and clarify for you. Kurt