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SCV
science forum beginner
Joined: 20 May 2005
Posts: 1
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 Posted: Fri May 20, 2005 5:14 am Post subject:
Hoffman degradation of amides
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Hi!!!!
My company produces acrylamide polymers. Currently, we are interested
in obtaining polyvinylamine polymers from acrylamide polymers through
the hoffman degradation.
Can anyone give me a hand???
Thanks a lot |
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Attila the Bum
science forum Guru Wannabe
Joined: 06 May 2005
Posts: 251
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| Posted: Fri May 20, 2005 11:21 am Post subject:
Re: Hoffman degradation of amides
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The test just came back from the lab -- your post smells like
tryptophan.
Take 27 of these little things before each meal. If your condition
doesn't improve within six months, go see a chemical engineer.
Mark |
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muha
science forum Guru Wannabe
Joined: 08 May 2005
Posts: 167
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| Posted: Fri May 20, 2005 1:42 pm Post subject:
Re: Hoffman degradation of amides
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I have done Hoffman degradation on simple molecules, not on polymers.
Typicaly you use a strongly alkaline solution of hypochlorite or
hypobromide (Chlorox bleach or brominating agent with NaOH). You
halogenate the amide bonds, then you heat up the haloamides to
rearrange to isocyanate and hydrolyse..
The trouble is that it is a messy reaction, goes through isocyanate and
with polymer it can cause crosslink. (Urea to other formed amino).
Also you will end up with a polymer with lots of amies, that will be
highly soluble in water and maybe poorly soluble in organic solvents.
Removal of salts may be a problem
It would be nice if one can solve the manufacture problem.
SCV wrote:
| Quote: | Hi!!!!
My company produces acrylamide polymers. Currently, we are interested
in obtaining polyvinylamine polymers from acrylamide polymers through
the hoffman degradation.
Can anyone give me a hand???
Thanks a lot |
|
|
| Back to top |
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Uncle Al
science forum Guru
Joined: 24 Mar 2005
Posts: 1226
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| Posted: Fri May 20, 2005 2:01 pm Post subject:
Re: Hoffman degradation of amides
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SCV wrote:
| Quote: |
Hi!!!!
My company produces acrylamide polymers. Currently, we are interested
in obtaining polyvinylamine polymers from acrylamide polymers through
the hoffman degradation.
Can anyone give me a hand???
|
Probably the Hofmann reaction or rearrangement. The Hofmann
degradation cleaves amines to olefins.
You had better look up the chemistry - and its yields! - before you
commit. Two major problems you will face are viscosity of polymer
solutions and opening new reaction channels (e.g., proximity of
isocyanate intermediates with products further along). Hypobromite is
reactive and expensive stuff. Hypochlorite may have better economics,
howver... RNHX and RNX2 will appear either way if you beat on it.
Merck Index, 13th ed., p. ONR-51
"Advanced Organic Chemistry," 5th ed, March, pp. 1411-12.
I'd cover my butt by looking into polymerization of H2C=CH-NH-acyl
monomers, like the formate.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf |
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