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General Science => General Science => Topic started by: Nanac on 17/05/2009 08:16:03

Title: water soluble linseed oil
Post by: Nanac on 17/05/2009 08:16:03

Hi, could any one please clarify what is water soluble/dispersible linseed oil ? how it is made ?

Title: water soluble linseed oil
Post by: Chemistry4me on 17/05/2009 08:34:21

Not totally sure but I guess one end of the molecule would be altered to bind loosely to water molecules.

Title: water soluble linseed oil
Post by: lyner on 17/05/2009 12:24:59

Linseed oil is used in circumstances where its insolubility is important, isn't it? A soluble version could well be a chocolate teapot. Perhaps an emulsion could be useful - it would separate out in time - like vinaigrette.

Title: water soluble linseed oil
Post by: Bored chemist on 17/05/2009 16:30:38

Nanac,
are you trying to make an emulsion paint or something?

Title: water soluble linseed oil
Post by: DrN on 17/05/2009 17:17:07

Sounds like an oxymoron to me. I thought oil was defined by being insoluble in water? I'm sure someone will correct me if I'm wrong!

Title: water soluble linseed oil
Post by: Bored chemist on 17/05/2009 17:38:42

Do you know what dispersible means?

Title: water soluble linseed oil
Post by: lyner on 17/05/2009 17:59:09

When I put 'dispersible' Aspirin in water it doesn't go clear.

Title: water soluble linseed oil
Post by: DrN on 17/05/2009 18:46:10

Quote from: Bored chemist on 17/05/2009 17:38:42

Do you know what dispersible means?

Was that an attempt at sarcasm, or a genuine question?

Dispersible is not the same as soluble.

Soluble indicates the substance completely dissolves, whereas dispersible indicates that it merely breaks down into minute particles.

There are applications for water soluble versions of certain substances - take oil paints. Artists like the texture and qualities of oil paint, but its very messy and takes ages to dry. Acrylics are pretty close to a water soluble version, but not close enough to replace oils.

Title: water soluble linseed oil
Post by: Bored chemist on 17/05/2009 19:15:41

The OP asked about oil thats soluble or dispersible. Since it can't be soluble we are left with looking at making it dispersible. That, to me, looks clear enough to prompt the question.

Title: water soluble linseed oil
Post by: DrN on 17/05/2009 19:32:57

So it was a question then? I apologise for jumping to the conclusion that it was sarcasm.

I must admit, I thought the very words 'soluble' and 'dispersible' make it pretty clear what they both mean.

This helps to explain part of the question, in terms of my oil paint example:
http://en.wikipedia.org/wiki/Water_miscible_oil_paint (http://en.wikipedia.org/wiki/Water_miscible_oil_paint)

So it would appear that the linseed oil can be alkali-refined to make it miscible, although I'm still not clear whether this actually makes it soluble (I suspect not, but don't want to say that out loud) or just dispersible.

Title: water soluble linseed oil
Post by: Bored chemist on 17/05/2009 20:01:42

Treating a vegetable oil like linseed with alkali and water will eventually turn it into a soap. I suspect that the "refining" process turns some of it into a soap and this will disperse the oil in water. I doubt it's strictly soluble but not everyone is that fussy about using the same words for the same meanings and I can see how painters and chemists might have different ideas.