On Sat, 14 Jan 2006 13:05:35 -0800, "Katharine Thayer"
<kthayer@pacifier.com> said:
> So maybe the "yellowing" could be a result of using more glyoxal than
> is required to crosslink the gelatin?
That's my most logical guess, and I've been saying that for years...
> I wondered about this here some time back, why it was considered
> "necessary" to use so much more glyoxal than glutaraldehyde, and I
> don't remember getting any useful answers to the question.
I've also mentioned this as a fact, and also posted a reference to
studies on reaction kinetics of crosslinking.
> So I've
> gone on using the recommended amount of glyoxal. But it sounds from
> this like much less would probably work fine. Has anyone actually
> tried this?
If you use the same amount of glyoxal as glut, the crosslinking reaction
would be far slower, even if the pH, etc. are adjusted to optimal
condition. The virtue of glut is that it works fast and throws a lot of
variables into the region that one wouldn't have to worry. I've been
saying this as well.
I have spent quite a bit of time testing hardeners for my sizing as well
as silver-gelatin emulsions, but for regular, straight gelatin, I've not
found a better agent than glut.
Received on Sat Jan 14 16:01:36 2006
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