Formaldehyde's funny stuff. It's naturally a gas. If you put too much of it in solution, it will polymerize and form a polyacetal, "paraformaldehyde," which is just -O-CH2- repeating over and over.
Because of this tendency towards polymerization, formaldehyde of commerce is sold with a little methanol added to keep it in solution. Interestingly, formaldehyde polymer is used as a plastic - and it's food approved! In some ways, it stands to reason - the stuff won't dissolve in much of anything so it's pretty chemically resistant. On the other hand, you can actually "crack" paraformaldehyde just by heating it (releasing formaldehyde gas), which makes it a little scary to think of it being in your kid's Hot Wheels.
- Log in to post comments
More like this
Well, the school science fair looms (as school science fairs are wont to do). While the actual event isn't until May, we have reached the point at which the science teacher is vetting the proposed projects.
Presumably the vetting is to ensure that the kids are directing their efforts toward a…
Just as the safety of the food supply is coming under increased scrutiny we have the Castleberry Foods botulism recall, now involving a variety of brands of Hot Dog Chili Sauce and dog foods. Both have something in common you wouldn't necessarily think of at first (unless you knew about botulism).…
After
href="http://scienceblogs.com/goodmath/2008/12/the_real_bozo_attempts_to_aton.php">the
fiasco that was my flame against the downwind faster than the wind
vehicle, you might think that I'd be afraid of touching on more air-powered
perpetual motion. You'd be wrong :-). I'm not afraid to…
Yesterday, we had an urge to do some experimentation and I had a red cabbage that had overstayed its welcome in the refrigerator crisper drawer.
So of course, we made cabbage-water indicator.
An indicator is a substance that produces a color change that gives you information about whether the…
Not only that, but you can accelerate breakdown of the crosslinkage with a few drops of NaOH.
Somehow I can't think about formaldehyde without mentioning Bakelite.
It's a lot more scary thinking of it in my food packaging.
Maybe you could help me understand something.
In our lab we have a variety of different fixatives. Formalin, formaldehyde (with methanol stabilizer), paraformaldehyde etc.
Now, from what I understand they all are essentially formaldehyde and crosslink based on the same mechanism of action, but what, other than absence of methanol or other stabilizers, is the difference between the different fixatives?
I've always just used paraformaldehyde, it works, is easy to make, etc., but is there any difference in their fixative ability?
(CH2O) n, a white powder - The dust may form an explosive mixture with air.
Delrin like Teflon is all about endcapping. With endcaps the polymers are tough as nails. Without endcaps they thermally unzip.
Where I work we use measured amounts of paraformaldehyde in 'fry-daddys' and turn them on to fumigate our labs (of course, I wouldn't recommend this at home without proper air-handling).
They used paraformaldehyde to kill the Ebola-ridden monkeys in Reston, VA