Today I will explain what hexaphenox is. As mentioned the term hexahenox is an artificial word. hex stands for hexamine, phen for the chemical name of the catalyst phenolphthalein and ox for oxidizer, which can be KNO3, KClO3, KClO4, NH4NO3, NH4ClO4 etc. You read right, the catalyst is phenolphthalein, often used in titrations, it turns colorless in acidic solutions and pink in basic solutions.
How I stumbled now just over phenolphthalein?
In a warm night at June I went depressed to bed, having tried more the 100 additives to oxidize hexamine with KNO3. As I fell asleep I had a febrile dream just like Friedrich August Kekulé had with his structure of benzene. My last year passed away father, a chemist, appeared in my dream and he gave me a small plastic bottle. I opened it and spread the white powder in it around. Everything the white powder touched, started to burn. Surprised I looked at the label of the bottle: phenolphthalein. After woke up in the morning I went immediately to my lab, mixed KNO3, hexamine and phenolphthalein with following result:
To be honest, I do not know exactly how it works. My theory is that hexamine decomposes partially to formaldehyde and ammonia in the presence of alkaline earth metal or alkali metal nitrates when heat is applied and ammonia cools the flame just like some flame retardants do and phenolphthalein prevents this somehow. Hexamine can be oxidized with KClO3 without the presence of phenolphthalein but it is very difficult to ignite. The video here shows the difference. The phenolphthalein change the ignition behavior dramatically, similar to sulfur in black powder mixtures. Phenolphthalein also prevents the formation of fuzed salty residues, which can even block the rocket nozzle. Using phenolphthalein the only residue left is flaked carbon which will be blown out from the combustion chamber easily and without doing any harm.
I am uncertain my discoveries will have any impact in rocketry. Time will tell. Sure is that bigger rockets with this propellant will be flown soon and it's worth to research further.
The current formula of hexaphenox is 75 % w/w KClO3, 15 % w/w hexamine and 10 % w/w phenolphthalein.
Thanks for reading.
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