Monday, September 13, 2010

Esters: Crodamol PMP or PPG-2 myristyl ether propionate

PPG-2 myristyl ether propionate (also known as Crodamol PMP) is a PPG ester that is soluble in aqueous and alcoholic systems and in oil based products. It's a clear, odourless*, light, high spreading emollient that behaves as a greasiness reducer and de-tackifier (click here for more on this topic). It will form light non-occlusive, dry-feeling films on our skin to give us a feeling of moisturizing without a lot of greasiness.

*Okay, before we go on I have to tell you this is not odourless to some of us. It has a weird vinegary scent that I and a few others have noticed. When I made a body oil with it, I had to add 4% fragrance oil to try to overcome at smell. I don't think my bottle was rancid - it has a really long shelf life - and I found it really awful. My mother and husband didn't think it was too bad, but my best friend and her husband found it offensive. If you're using it at 3% in a body wash, you won't notice it - straight out of the bottle is really over the top and 10% in a body oil was too much for me. And I'm really annoyed about this because it's an amazing feeling ester with so many uses! I'm not saying you shouldn't use it and perhaps you won't notice the odour, but I wouldn't use it in an unfragranced product! This could be like BTMS-50 - some people notice a fishy odour, most people don't - but I've never had anyone who could smell the fishiness in a conditioner even at 10% usage in an unfragranced or 1% fragranced product. If you've had any experience with this ester, could you please post your thoughts on this ingredient in the comments? It would help greatly! Back to the post...

Crodamol PMP is used as a replacement for oils in emulsified products and body oils at 2% to 20%, and can be used in water based products like surfactant systems, much the same way we've been using Cromollient SCE, and you will get a clear body wash or shampoo with it! It can be used in place of mineral oil or castor oil in lipsticks as a degreasing ingredient. 

It behaves as an emulsifier, so it can be used to include oil based ingredients into water or alcohol based systems, so if you wanted to use a little more oil in a surfactant system or in a water based spray, you can use a little Crodamol PMP to help solubilize those oils! 

I see Crodamol PMP as being the meeting point of all the various esters as it can be used in water soluble and oil soluble products easily. It behaves as a very light oil that can be included in pretty much every product we make from body washes and hair care products to lotions and body oils. We can use it in place of the oil soluble only esters - like C12-15 alkyl benzoate, ethylhexyl palmitate, and cetearyl ethylhexanoate - and it can be used in place of the water soluble esters - like PEG-7 olivate, Crodamol STS, and Cromollient SCE. Because it behaves as a solublizer, you can use it to integrate small amounts of oil based or water based ingredients in normally aqueous or anhydrous products! (They do mean small amounts - I tried putting 5% water based ingredients into a body oil spray and it separated. So I'd keep the amount really really small for water based ingredients in an oil based products. It works very well to solubilize oils or fragrance oils into watery'll see that in a few days!) 

And it has another interesting feature - it can be used to reduce the freezing point of our products. Let's say you have a body wash or bubble bath or lotion you want to send to a friend in northern B.C. as a Christmas present. Add a little Crodamol PMP to the mix - 2% to 5% - and you can ensure it will reach her in a liquid state. (As a note, humectants like propylene glycol and glycerin also do this!) Probably not a big concern for most of us, but considering there's a titer point for surfactants where they'll go cloudy and stay there, if you live in a cold climate where your unheated workshop might see a little freezing of your products (yep, my oils can freeze in my workshop in winter, but I see that as a way of extending their shelf lives!).

Join me tomorrow for an aside on formulating deodorants and the next day for using this ester in an alcohol based one! 

1 comment:

Kelli Spears said...

Hi Susan,
I saw your post on Crodamol PMP and just recently had the opportunity to experiment with this ingredient. You asked people to comment on their experiences with it. I did smell it when I first got it and you are right. It does have a pronounced vinegary scent. I did not find it overwhelming or overly offensive out of the bottle so I decided to include it in a new shampoo formula instead of using the Cromollient SCE. I used it at 2% and the end formula had not even a hint of the vinegary smell. All I could smell was the typical surfactanty smell that I consider normal before adding any fragrance.
The shampoo turned out fantastic and I would use this ingredient again in other formulas, not just surfactant type formulas. I do love that it is both water and oil soluble. I purchased mine from The Personal Formulator, which is the only place I've ever come across it, and I think their prices are very reasonable and the shipping is quite fast.