Benzotriazole Shelf Life?

[maxbloom]

Can anyone comment on how long this will keep in solution? Thanks.

 

[Tom Hoskinson]

Can anyone comment on how long this will keep in solution? Thanks.

in my experience, Benzotriazole keeps pretty well in slightly alkaline solutions. Take a look at this photo.net thread:

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=0097vg

 

[Snapshot]

My 1% solution in tap water seems to work and it's been about a year. My tap water is slightly alkaline (about 7.6 ph) so this might be a factor.

 

[maxbloom]

Any recommendations on an appropriate alkaline additive to my neutral pH water?

 

[Murray@uptowngallery]

What about dry BZT shelf life?

 

[Tom Hoskinson]

What about dry BZT shelf life?

from the thread link I posted earlier:

Benzotriazole can also decompose slowly in alkaline solution. A neutral organic solvent is best for long shelf life.

Ethyl, Propyl, or Methyl alcohol are best.

Ron Mowrey

 

[Snapshot]

Sodium sulphite is alkaline. A small amount will do, probably in the range of a 1% solution (10g per litre), which should give a pH in the neighborhood of 7.5 or so. A 5% solution will give a pH of 8.0 or so. This could have some impact on photochemical reaction depending on how it is used. However, you'll likely be using a small amount benzotriazole so it may not matter. Isopropyl alcohol would be a good liquid to dissolve in as well.

 

[maxbloom]

I'll give isopropanol a try. AFAIK it's generally the least reactive of the three.

 

[Wayne]

from the thread link I posted earlier:

Benzotriazole can also decompose slowly in alkaline solution. A neutral organic solvent is best for long shelf life.

Ethyl, Propyl, or Methyl alcohol are best.

Ron Mowrey

Hmmm...all the alcohols I know are quite WET.

I think dry BZT lasts a very long time. I've had no trouble using stuff that is years old.


Wayne

 

[john_s]

Benzotriazole is used in boilers as a corrosion inhibitor. Since it lasts well in those conditions it should last quite well in a bottle of solution in the home. It dissolves better in mild alkaline solutons. Sodium sulphite is alkaline enough to improve its solubility. This what the old Orthazite solution was.