Friday, August 17, 2012

Questions I've seen this week: Cetyl esters or alcohol,

In this post, Anastasia writes, When you have time for a question (totally for my own info!), I am having trouble understanding the difference between cetyl esters and cetyl alcohol. When would I use one over the other? Thanks!

In this post on formulating and using thickeners, I take a look at what each fatty alcohol, ester, or acid brings to the product. Cetyl esters tend to be lighter and glidier than cetyl alcohol, but they don't seem to play well with vanilla based ingredients. Which one you want to use depends upon your personal taste. As you can see from the recipe in the link, using cetyl alcohol will create a thicker product that has slip and glide, whereas cetyl esters will create a thinner product with slip and glide.

I have cetyl esters in my workshop, but I tend to reach for the cetyl alcohol just about every time (although behenyl alcohol is appearing more and more in my products because it's awesome!). It really is about the skin feel you prefer.

In this post on substituting ingredients in emulsified sugar scrubs, Bajan Lily writes Lovely post as always. I was just wondering why you used the polawax at 10% instead of at 25% of the oil phase? Does it matter in this product or is that level more relevant for creams and lotions?

The emulsifier is essential for this product, but you can play with the levels. We aren't using it at 25% of the oil phase because the product is pretty much all oil phase and 25% Polawax or e-wax in this product feels just awful. (Yep, I tried it! It was horrible!)

The really short answer is that I've tried many different levels of emulsifier, and it seems like 10% is the ideal amount. Anything over that and it feels kinda waxy. Anything under that and it doesn't seem like it rinses off well.

The rule of thumb when using Polawax is that we use it at 25% of the oil phase. So in a lotion with a 30% oil phase, we'd use it at 7.5%. Click here for more information on this rule of thumb! 

Related posts:
Better crafting through chemistry: Cetyl alcohol
Esters: Cetyl esters
Learning to formulate: More fun with thickeners
Using Polawax in your creations


Anastasia said...

Thank you for answering my question! That totally makes sense. Time for me to do some experimentation :)

Bajan Lily said...

Thanks as well. I didn't even consider the repercussions of the product being mostly oil, which would translate into 25% of the oil phase being very high! d'oh! Thanks for a brilliant and informative response (as always!)