The first thing that spring to mind is Nile Red - that should be
fairly unreactive in your composition. And it is lipophilic so should
dissolve in your HTPB/plasticiser.
There's an OH group in E129 that I might worry about reacting with
your isocyanate.
Please let us know how you get on, I'd be interested to know!
On Fri, 24 Aug 2018 at 14:07, DH Barr <dhbarr@xxxxxxxxx> wrote:
I think your typical red food dye is fd&c red 40 / e129, for example. The
Internet tells me that's
Disodium
6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate
... which sounds a bit hard to predict, but the Sodium/Potassium/Calcium
possibility, Sulfur possibility, and/or sometimes Aluminum tends to make me
think there might be some unanticipated interactions.
On Fri, Aug 24, 2018, 12:07 AM Brett Coles <brettcoles@xxxxxxxxx> wrote:
Would Red Food dye work? I know it is generally used with water soluble
things (like food), but it will color cookies. (They have a lot of oil....)
On Thu, Aug 23, 2018 at 3:36 PM Harry Amadeo <harryamadeo@xxxxxxxxx> wrote:
That could be it. That's definitely green.
On Thu, Aug 23, 2018, 14:18 Brett Coles <brettcoles@xxxxxxxxx> wrote:
Maybe he's using Chromium(III) Oxide? That's green.
On Thu, Aug 23, 2018 at 10:50 AM Harry Amadeo <harryamadeo@xxxxxxxxx>
wrote:
Wait a minute,
Charlie, where were you getting green copper chromite? I use copper
chromite in my propellant, but the stuff I get is all black (from RCS).
Cheers,
Harry.
On Thu, Aug 23, 2018 at 12:01 PM Terry McCreary
<tmccreary@xxxxxxxxxxxxxxx> wrote:
One other issue...avoid dyes that have reactive hydroxyl groups. A long
time ago I discovered that methyl salicylate (oil of wintergreen) could
not be used to make propellant smell pleasant, as it didn't play well
with isocyanates... the phenolic hydroxyl group was the culprit.
On 8/22/2018 8:06 PM, Charlie Garcia wrote:
The purpose of coloring them is primarily aesthetic. Our old propellant
was a delightful shade of green from the copper chromite. Dying the new
ones will make them easy to distinguish ( not that that's necessary) and
fun.
Other than staying away from TMO's and chemicals ending in -cene, are
there any other dye chemistries that are likely to significantly change
the burn rate.
Thanks for the suggestions. We'll report back if we discover one that
works.
Sincerely,
Charlie
On Wed, Aug 22, 2018, 4:19 PM Terry McCreary <tmccreary@xxxxxxxxxxxxxxx>
wrote:
I've not done so, but the organic---no metallic elements and no
minerals---dyes used to make smoke bombs or dry organic pigments used to
make oil paint might be worth trying, as they are unlikely to affect
ballistic characteristics significantly in small quantities. You'd need
to know the actual formula or composition of the dye; for example,
viridian pigment is a form of chromium oxide and would increase the burn
rate.
Best -- Terry
On 8/22/2018 12:48 PM, Charlie Garcia wrote:
Hi All,
Does anyone here deliberately dye their grains, like AeroTech or CTI?
In particular I'm looking for a red dye, preferably in very small
fraction or a liquid. I've had the red dye that comes in RocketPoxy
suggested to me. Thoughts?
Sincerely,
Charlie
--
Dr. Terry McCreary
Professor Emeritus
Murray State University
Murray KY 42071
--
Dr. Terry McCreary
Professor Emeritus
Murray State University
Murray KY 42071
--
So long and thanks for all the fish.
--
Brett J. Coles
--
Brett J. Coles