[AR] Re: HTPB Dye

  • From: Terry McCreary <tmccreary@xxxxxxxxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Thu, 23 Aug 2018 10:58:48 -0500

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 <mailto: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

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