[liquidsoap]

Hello! This is my first post in here and I hope to be both of help to you and get some help from you too

Anyway. I have a mixture of potassium soap (made of vegetable oil fatty acids), polymer (alkoxylated alcohol - nonionic surfactant) and amphoteric surfactant (cocamidopropylbetaine).
How to decrease the freezing point down to -10C?
The best way is to add NaCL, which obviously salts out the potassium soap and I end up with a totally 'broken' formulation. Adding KCl, apparently does the same thing which I cannot explain as K is K and nothing shall get salted out, but the solution 'breaks' anyway.

What to do?

Many Thanks.
Wendy

[Arkcon]

Hrm ...

Ok.  You have water with some solutes in it.  They should lower the freezing point somewhat.  Its hard to calculate for such a complex mixture, you should determine experimentally.  Note:  freezing doesn't mean thickening, which is what you're likely to get with your mixture.  So you'll have to differentiate.

Adding NaCL will lower the freezing point, as solutes tend to do.  But adding NaCl has the effect of binding up water, which causes other things to precipitate.  Your described "salting out" effect.

The common ion effect is why adding potassium salts cause potassium soap to precipitate.

You can try any of a number of other salts, but I'd start with first determining how low the freezing point already is, and then trying to lower it further.

[liquidsoap]

Thank you for your input Arkcon. The actual FP is -2C, now. You are right about the thickening. Are there any simple additives that can also hinder that?