Thursday, August 15, 2013

Another Monomer I Won't Work With

I've written in the past of not wanting to work with urushiol as a monomer, despite it be biobased and producing some incredibly beautiful lacquers. It's just that the whole idea of working with the active allergen from poison ivy gets my skin crawling (pun intended).

I'm adding another monomer to the list, or more correctly, a polymer made from such monomers. Angewandte Chemie has a short review in it's latest issue entitled "Growing Cantenated Nitrogen Atom Chains".
These are (blessedly) short chains with an all nitrogen backbone. So far, the best efforts have only reached 11 nitrogen atoms, so it is still too short to call a polymer [*]. The N11 compound shown is actually too unstable to exist on its own and it must be cocrystallized for further handling. The reason is that all that nitrogen is just waiting to return to the N2 from which it originally came and it will give off lots of energy (~ 1500 kJ/mol !) in the process. So not only do you have a large volume change associated with the solid polymer degenerating to a gas, but you also have heat to further energize it. Whether this occurs as an explosion or a deflagration, I really don't care as I'm not going to be anywhere near it. If someone else is interested enough to make these polymers, go for it. You won't have much competition. And if you're not careful, you won't have much left of your fingers either.

[*] My operation definition of a polymer is a chain long enough that the addition of one more monomer does not change the properties of the material. This is truly operationally defined as depending on what properties you are examining, that length may vary.

1 comment:

Olivia Mak said...

Science is such a fascinating, yet mysterious thing. I just started getting into chemistry for my classes and I never knew how useful something like GMP monomers are in our everyday lives.