Home Cosmetic Science Talk Formulating Dissolving Stearic Acid

  • Dissolving Stearic Acid

    Posted by Anonymous on November 4, 2016 at 8:01 am

    Hi,

    Can I use peg-60 hydrogenated oil or cocamide DEA to dissolve stearic acid? 
    If yes, what is the ratio?

    Also I intend to use Stearic Acid to make my foams denser. 

    Thanks

    Chemist77 replied 8 years, 2 months ago 4 Members · 16 Replies
  • 16 Replies
  • crisbaysauli

    Member
    November 7, 2016 at 11:48 am

    Hi. Why do you need to dissolve stearic acid? Are you going to use it as an opacifying or pearlizing agent for a rinse off product?

  • Anonymous

    Guest
    November 8, 2016 at 7:16 am

    @crisbaysauli hi. currently, i would like to experiment with stearic acid and it’s ability to make foam denser. therefore, i have no oil phase for the stearic acid to dissolve in. which is why i would like to include a solubiliser. 

  • johnb

    Member
    November 8, 2016 at 9:23 am

    Is this for your face wash idea?

    Stearic acid would be near the bottom of my list of choices in this type of product -probably not make it at all.

  • crisbaysauli

    Member
    November 9, 2016 at 3:06 am

    @myspareacc21 I agree with @johnb. You might want to use EGDS (ethylene glycol distearate) instead, which you can solubilie in CDEA with heating up to 70 degrees. This makes for a nice white pearly appearance for washes, and may add to the density too

  • Anonymous

    Guest
    November 9, 2016 at 6:34 am

    @johnb yes, it is. i was just experimenting. since stearic acid should not be used, (@crisbaysauli) what can you recommend me to use for increasing foam density while still obtaining a clear formulation? 

    @crisbaysauli thank you for your suggestion however i am not looking for a pearly finish product 🙂 

  • johnb

    Member
    November 9, 2016 at 9:25 am

    As well as just looking at ingredients lists, it is often worthwhile interpreting what the ingredients may have been converted to during manufacture.

    A quick glance at the LOI of the product you are trying to emulate tells me immediately that the principle foaming agent is a potassium laurate based soap (lauric acid, potassium hydroxide, myristic acid, palmitic acid). The foaming propensity is enhanced by PEG-150,Laureth-6 carboxylic acid, lauryl hydroxysultaine.

  • belassi

    Member
    November 9, 2016 at 3:09 pm

    It’s a Kao product. Contains Akypo RLM45-CA.

  • johnb

    Member
    November 9, 2016 at 3:26 pm

    Akypo RLM45-CA is the laureth-6 carboxylic acid.

  • Chemist77

    Member
    November 10, 2016 at 3:57 pm

    A very versatile product indeed that Akypo thingy!!

  • belassi

    Member
    November 10, 2016 at 5:36 pm

    It’s a really excellent surfactant. Don’t need much of it because it is almost pure active.
    In the LOI above, it looks a bit deceptive. I suspect that the lauric acid,myristic acid, palmitic and etidronic are components of one or at most two oils. The KOH is used for saponifying that, but also for neutralising the RLM-45CA. Seems to be huge amount of sorbitol in it if we can believe the label.
    Here is a similar recipe.

  • johnb

    Member
    November 10, 2016 at 6:24 pm

    Editronic acid is a phosphonate chelating agent, not a fatty acid.

    I very much doubt that lauric acid,myristic acid, palmitic acid are included in the form of oils then to be saponfied in situ by the KOH (where is the glycerine of the sap reaction?)

    I agree that there is seemingly a huge proportion of sorbitol, also PEG-150.

  • Chemist77

    Member
    November 11, 2016 at 1:31 pm

    I would check the pH first to make any judgement, if it is 8 and above then it is definitely soap based. If not then synthetics are main here and the rest of the LOI is just a hogwash, ignore. Also this comes quite close to the LOI of Lifebuoy hand wash which is based on these fatty acid soap, you can tell by the look of it. 

  • johnb

    Member
    November 11, 2016 at 2:24 pm

    There is confusion being generated here.

    There is little or no doubt are present in the form of soaps. The point is that these soaps are formed by the in situ neutralization of fatty acids by the KOH, NOT by saponfication.

  • Chemist77

    Member
    November 11, 2016 at 2:32 pm

    I ignored the fact that the product is from Kao so I would accept the product as it is, it is soap based and and the pH must be above 8 surely. 
    No confusion here @johnb, just a different perception. 

  • belassi

    Member
    November 11, 2016 at 5:51 pm

    Not necessarily. The RLM-45CA requires neutralization. It could equally well be that the fatty acids are present as fatty acids. Measure the pH and let us know.

  • Chemist77

    Member
    November 11, 2016 at 6:11 pm

    @Belassi that’s why I mentioned the Lifebuoy reference, have done it in lab but not with Akypo of course. The pH was around 9 almost. 

Log in to reply.

Chemists Corner