Alternatives to starch

Alex Nanson (alec@norlex.demon.co.uk)
Sun, 28 Jul 1996 18:26:24 +0100

In message <Pine.SUN.3.91.960727225217.22678L-100000@panix2.panix.com>,
Judy Seigel <jseigel@panix.com> writes
>
>On Sun, 28 Jul 1996, Alex Nanson wrote:
>> I posed the question, because as an ex surface coating chemist it seemed
>> to me [silica] to be the obvious substance to investigate as a means of
>imparting > 'tooth' to a coating as an alternative to starch.

>Please, what's the matter with starch? (Or as I recall the formula was
>for dextrine.) Why the "alternative"?

There is nothing at all wrong with starch as far as I know. Why the
alternative? Its the way my mind works I'm afraid. I am just as
interested in the chemical and physical properties of alt-processes as I
am in the final image. Hence the interest in alternatives to the
original materials.

I must also confess to looking for various synthetic water soluble
alternatives to gum arabic, albumen, and gelatine. Has anyone any
experience of any such alternatives?

>
>Also, many years ago I bought a Johns-Manville (pre-bankruptcy) product
>called "Celite," a Diatomite Functional Filler, which came in various
>grades & was very inexpensive, for use as a flatting agent. The label
>notes that among other functions it is "a delicate abrasive", etc. etc. It
>worked fine. I didn't get silicosis (yet).
>
Ah Celite! I remember it well, we used it as flatting agent in un
dercoat paints.

>But as I say, why not dextrine?
>
>Judy

I think that Dextrin is actually starch which has been partially broken
down (hydrolised) by treatment with dilute acids, to produce a gum like
substance easily soluble in water, and thus it would not behave in same
manner as starch.

Alex
Alex Nanson
Gloucester UK