Re: Gum print formaline

Katharine Thayer wrote:
>
>
> Does anyone have any information re relative amounts of glyoxal and
> glutaraldehyde required to produce an equivalent degree of
> crosslinking?

Since the two materials produce different kinds of crosslinks, perhaps
it's not an entirely answerable question, but by "degree of
crosslinking" I really meant the practical effect of relative hardening
in the sense of resistance to swelling and to being dissolved by boiling
water. It's said that the crosslinks formed by glyoxal in gelatin aren't
stable to boiling water (Burness & Pouradier) but I certainly didn't
find that to be true with gum; a rather astonishingly small amount of
glyoxal in gum rendered it so hard that neither cold nor boiling water
could budge it. So I'm just curious why it takes so much glyoxal to
harden gelatin, but as I said, the mechanisms may be entirely different
for the action of glyoxal with the two colloids.
kt
Received on Mon Jan 31 11:57:48 2005