Wednesday, October 12, 2011

Question: Mixing oils and water

In the most recent what do you want to see? post, Ben writes: Hi Susan! I thought I'd ask you a simple "I want to know" request. I was wondering about the mixability of jojoba oil. Does it mix well with water, or does it need an emulsifier? What about mixing with oils? Also, beeswax for the same above question. 

Jojoba oil and beeswax are composed of lipids or fats (click here for more information on triglycerides) and neither of them will mix with water without an emulsifier. They will mix well with oils because jojoba oil and beeswax can be considered oils for our purposes. Jojoba oil is a wax ester and beeswax is a wax.

So what exactly is a wax? There are two main groups of waxes - natural and synthetic waxes. Natural waxes include hydrocarbon, mineral, vegetable, and animal waxes. Synthetic waxes include polymer waxes, usually called synthetic wax (wow, that was helpful, eh?) To quote Wikipedia: "Wax refers to a class of chemical compounds that are plastic (malleable) near ambient temperatures. Characteristically, they melt above 45 °C (113 °F) to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents."

And what is a wax ester? Esters are chemical compounds derived by reacting an oxoacid (one containing an oxo group, X=O) with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group, and most commonly from carboxylic acids and alcohols. They can be found naturally - for instance, in jojoba oil - or can be synthesized from fatty acids. A wax ester would be plastic near ambient temperatures and insoluble in water.

And what exactly is the deal with beeswax? (From this post on waxes): Beeswax is composed of 70% fatty esters and 10 to 13% hydrocarbons, and offers hardening properties as well as plasticity to products. Its melting point is 50˚C to 55˚C. As with other waxes, it is insoluble in water but soluble in oil.

As both of these ingredients are oil soluble, you can only have them mix with water if you use an emulsifier!

2 comments:

Ben said...

You are a goddess! :D Thanks! ;)

Nedeia said...

talking about beeswax, I wanted to make myself a super stiff hand cream, for the harsh cold winter weather + gardening, when I tend to avoid gloves.

It goes like this:
80% green tea infusion
10% beeswax
3% glycerin
2.5% polawax
2.5% cetearyl alcohol
1% optiphen
1% amyris balsamifera EO

Heat & hold for 10 minutes ( I was in a rush) at 70 celsius. Pour water phase in the oil phase (I hate to loose the wax on my beaker, which always happens). start mixing.

No emulsion whatsoever. After 10 minutes of mixing, I see separation.

Now the questions:
- was my beeswax percent too high? Is there a recommened percent for using beeswax? I know, I wanted maybe TOO MUCH, I usually use 2 grams for a 100g batch, in conjunction with other oils
- was there too little polawax? am I to count the cetearyl alcohol too when calculating the % of polawax? I used 25% of 10 grams of beeswax, should I have calculated 25% or beeswax+ cetearyl?

My scale is quite accurate (0.01g), so everything was measured correctly.

I am puzzled :) I am going to try to make the cream with only 5% beeswax and add an oil/butter...

Thanks for the help :)