Sciencemadness Discussion Board

Aluminium octoate synth.?

kazaa81 - 15-5-2004 at 13:19

Can anyone tell me about a strange compound, aluminium octoate?

Thanks for help

FritzHaber - 15-5-2004 at 13:33

Quote:
Originally posted by kazaa81
Can anyone tell me about a strange compound, aluminium octoate?

Thanks for help

aluminium octanoate, Al(n-C7H15COO-)3 is a simple salt of Al(3+) and octanoate anion, which is an ion derivated from octanoic acid (=8-C-chained lower fatty acid with one carboxyl group)

synthesis? I guess a precipitation of an alcalic salt of octanoic acid (e.g. sodium octanoate) by adding saturated cold aqueous alum should fit it...
its a minor constituent of WW2 napalm receipes ...

[Edited on 15-5-2004 by FritzHaber]

Octanoic acid from oleic acid?

kazaa81 - 15-5-2004 at 13:39

Thanks for help Fritz!
Can be synthetized octanoic acid that you have writed about, from an other fat acid, like oleic or palmitic?

Really a napalm ingredient? Only as gelling agent, I think, or has Al octoate any incendiary propriety?

FritzHaber - 15-5-2004 at 13:46

Quote:
Originally posted by kazaa81
Thanks for help Fritz!
Can be synthetized octanoic acid that you have writed about, from an other fat acid, like oleic or palmitic?

Really a napalm ingredient? Only as gelling agent, I think, or has Al octoate any incendiary propriety?


well, maybe its possible to carry out an destructive oxidation of higher fatty acids to break the chains forming octanoic other lower alkanoic acids...but I think the most appropriate way of preparing octanoic acid would be oxidation of n-octanole, hydrolysis of octanonitrile or similar. depends on purpose you need the acid to, and thus the needed purity.

and yes, it was in fact a thickening agent...but the original WW2 Napalm consisted of about 1:1 ratio of Al(3+)salts of naphtenic acids (these are middle-long chained alkanoic acids, octanoic included, produced by permanganate-catalysed air oxidation of paraffins) and those of coconut palm oil abundant fatty acids.

[Edited on 15-5-2004 by FritzHaber]

Text about fat acids synth.

kazaa81 - 15-5-2004 at 14:25

Can you tell me a good read for fat acids preparation, a book, web pages, pdf etc.?

Thanx

Aluminum Octoate

stresen - 20-12-2004 at 12:25

Aluminum Octoate was invented by my family and we held the patents. It was indeed used as a gelling agent in Napalm in WWII and also was a very good gelling agent for specific inks and paints.

JohnWW - 20-12-2004 at 20:09

Almost any water-insoluble metal salt of a fatty acid, or of "naphthenic acid" (cyclohexanecarboxylic acids as a byproduct of refining certain crude oils), i.e. a "metal soap", will do for that purpose. I suppose, though, that using aluminium has the advantage of its being trivalent and of relatively low atomic weight, meaning that it has about the highest possible content of fatty-acid or naphthenic acid groups for the weights of such compounds, compared to other metal soaps.

Cu and Zn metal soaps, especially naphthenates, are used widely also as wood or cellulose-fiber preservatives, applied by either painting or immersion, dissolved about !:3 in kerosene or turpentine.

unionised - 21-12-2004 at 10:16

Octoate is not the same as octanoate.