chemical resistance of materials

[ligrad]

Hi all,
I am loocking for some informations about the chemical resistance of acetal resin (Delrin), copper and titanium parts in LiOH, NH4OH, GdNO3 environments.

Thank you!
Ligrad

 

[Eltron]

For you ammonium hydroxide queries: Copper is not recommended (10-100% at 70°F); Titanium gets an A at 100% to 212°F; Delrin is not recommended for use. As for lithium hydroxide: Delrin is not recommended (10% at 200°F); Copper gets a B rating (100% to 500°F); and I don't have any data on Titanuim. Sorry, but I don't have any compatibility information on Gadolinium Nitrate.

Hope that helps.

 

[JimCasey]

Probably the industry standard for material compatibility is the "Compass Corrosion Guide"
Also, consult with your suppliers of Delin and the alloys for their recommendation of compatibility, AND with the manufacturers/suppliers of the reagents that you list. If you are buying GdNO3 from a company, they have to be keeping it in something, right?

 

[71cuda]

Regarding Gd(NO3)3, I see that the electronegativity and 1st ionization potential of Gd is along the same lines as Al, which readily forms hydroxides and oxides. For Gd, then, you could look at the worst case scenario (assuming aqueous solvent), which would be full dissociation of Gd(NO3)3. The equation would be:

Gd(NO3)3 + 3H2O -> Gd(OH)3 + 3HNO3

From this, we could say that the suspected reactive agent in water would be nitric acid. According to the chemical resistance charts provided by Cole Parmer (

http://www.ColeParmer.com),

titanium will be fine in nitric acid up to 72ºF (22ºC). However, copper and Delrin are not recommended.

I hope I will not get flamed too much for my back-of-the-envelope approach here.

 

[jsummerfield]

See if you have access to Corrosion resistance tables by Philip A. Schweitzer.

John