While we're on Acrylamide....

Peter pxpst2 at SPAM.SUXS.unixs.cis.pitt.edu
Mon Aug 3 11:58:59 EST 1998


In article <35C4E44A.2C43 at bcc.orst.edu>, fordb at bcc.orst.edu wrote:

> Peter wrote:
> > 
> > In article <6q0r1j$32e$1 at nnrp1.dejanews.com>, weazel at blarg.net wrote:
> > 
> > > Any of you chemistry-saavy types know what sort of nastiness one is
exposedt
> > > to from BURNING acrylamide? Say....when your gel box arcs and catches on
> > > fire? Not that this has ever happened to me, of course (heh heh!)
> > >
> > 
> > An arc would not be sufficent to cause the acryilamide to burn because
> > Arylamide is not flamable by nature.  But if you placed the gel in a bomb
> > calorimeter and ignited it, you would find CO, CO2, and CN.
> > 
> 
> The original question says acrylamide, but of course most if not all of
> a mature gel will be polyacrylamide. Even if polyacrylamide were
> flammable, it would be very hard to openly ignite a polyacrylamide gel
> containing 90 to 95% water. But, if we were really talking about the
> monomer, then consider that the heating of unpolymerized acrylamide
> solid to its melting point leads to rapid, and if the quantity involved
> is larger, to explosive polymerization. 

This is not what was asked.  Man are you just being wordy or what?
As for what you are saying...What unadulterated garbage.  since I have no
intention of teaching you about reaction kinectics, Suffice to say that as
a gas the molecules that will not polymerize faster than a liquid.

> This is perhaps another argument
> for using the, available and actually less costly, pre-prepared 40%
> acrylamide/bis-acrylamide solutions, for example from Amresco-- (no
> connection to me)-- and store in the fridge after opening. A lab fire is
> bad enough without extra explosions.


More words with little said



> 
> The bomb calorimetry seems a bit incomplete here. CO (carbon monoxide,
> often a fuel of industrial origin and use) will readily burn to CO2 in
> the calorimeter. CN or C2N2 (cyanogen) "burns with a pink flame"
> according to the Merck Index, the complete combustion products of which
> I would guess to be CO2 again and one or another nitrogen oxide such as
> NO or NO2. 
Well I will admit that NO2 should be included but while we are at it, PNAs
will be formed as well and the amount of each product formation will be
dependant on the pressure and  the percent oxygen in the gas phase of the
Bomb.

> 
> If by chance the accidental burning of polyacrylamide led to the
> evolution of CN or HCN then the questioner should be concerned. But a
> good fire (supplying the oxygen and heat of activation) would likely
> leave little free CN... cyanogen and oxygen produce one of the hottest
> flames known-- well above oxyacetylene or oxyhydrogen torches in
> temperature. Of course the toxicity of CN (similar to cyanide) keeps it
> even from consideration as a practical flame, anyway these days there
> are much better ways to heat stuff way hot!

More words with little said.  Once again Bryon's mouth is moving right along.

Peter

-- 
"Don't you eat that yellow snow
            watch out where the Huskies go"    FZ

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