Home Cosmetic Science Talk Formulating Neutralising a carboxylic acid

  • Neutralising a carboxylic acid

    Posted by belassi on November 28, 2014 at 8:41 pm

    As you might know I am trying to reformulate my sulphate-free shampoo to use less thickener.

    It occurs to me that I might try using MEA, which is a base, to neutralise the primary surfactant (Akypo RLM 45, a carboxylic acid)
    At the moment I use NaOH to neutralise it.
    MEA is a foam enhancer as well as a thickener. I’ll have to try it and see.
    belassi replied 9 years, 3 months ago 4 Members · 12 Replies
  • 12 Replies
  • RawMaterialGirl

    Member
    November 29, 2014 at 1:16 am

    AMP is also pretty handy. I try to avoid MEA at all costs, but then again I work with hair color.

  • belassi

    Member
    November 29, 2014 at 1:41 pm

    Been working with this today with excellent results so far.

    I discovered that MEA doesn’t neutralise the laureth-6 carboxylic acid. I guess it is too weak a base. So I still had to use NaOH to neutralise, just a little less was all.
    However, I discovered that adding 1% MEA to the formula and at the same time reducing the VLT thickener from 3.8 to 2% was overkill! I actually exceeded my target, the test shampoo when it was at room temp, was so thick it would hardly come out of the bottle.
    The foam profile is definitely improved!
    This is super important to me because our sulphate-free shampoo is becoming more and more popular, and my materials costs are going through the roof. The thickener went from $25/Kg to $40/Kg. This reformulation should allow me to control my costs and maintain my selling price. 
  • bill_toge

    Member
    November 29, 2014 at 6:43 pm

    @Belassi just got to warn you that MEA has a nasty habit of turning formulas yellow/brown, particularly at high levels; it’s something to bear in mind if the colour is an important aspect of this product

  • chemist77

    Member
    November 29, 2014 at 9:07 pm

    @Bill_Toge Can it be arrested (yellowing) by adding a little chelate or HS UV absorber?????

  • RawMaterialGirl

    Member
    November 29, 2014 at 9:12 pm

    That would be interesting to know (if yellowing can be arrested). I would be surprised.

    @belassi - can you try neutralizing with 2-amino-2-methyl-1-propanol? I’ve had success with this and the similar carboxylic acid you’re using. MEA can be damaging to hair over time, and if someone is using oxidative color and there are unreacted dye molecules in the hair, it can be a nightmare on their color. Of course, all depends on how much you’re using… But as a color chemist a main reason I avoid MEA.

  • belassi

    Member
    November 30, 2014 at 1:48 am

    I’m looking at using just 0.7% in the formula according to the results of today’s test batch. I was in Walmart today so I methodically checked all the sulphate-free shampoos. Pretty much all of them had MEA and some DEA as well which seemed a little over the top. Otherwise the rise in cost of the thickener causes a 25% price increase and kills the product.

  • belassi

    Member
    December 1, 2014 at 6:00 pm

    Today’s work on this, I increased the MEA to 1% and ran a 1.5Kg test batch. The Q/S for the VLT was now 2.2% indicating, I suspect, measurement errors for the 0.5Kg batch. (I have big problems measuring and incorporating small amounts of the thickener because it is like handling a thick, very sticky, glue)

    Well, that’s a lot better than having to use 3.7% but I am not quite there yet. I wish I had all the thickeners available that you have in the USA.
    Having said that, a quick check on EBay and Amazon indicates that (eg) Konjac powder actually costs MORE than my current thickener :(
    One of my suppliers has PVP so I will ask for the price of that.
  • chemist77

    Member
    December 1, 2014 at 9:05 pm

    But PVP is actually soluble in water and I am a little bit confused here if it is really going to help in thickening.

  • belassi

    Member
    December 1, 2014 at 11:20 pm

    Well I certainly hope it IS soluble in water or I will be in trouble! (grin) but I don’t yet know the price.

  • chemist77

    Member
    December 2, 2014 at 1:04 am

    Once it is solubilized completely I don’t think it is going to help in viscosity, as for the price it is around USD 15 for a 500 kg quantity from BASF (bought it pretty recently for my hair gel as a fixative). 

    There are few Chinese players too who sell it around USD 10 approx. 
  • belassi

    Member
    December 2, 2014 at 10:49 am

    Thanks. I should get there in the end. (I hope)

  • belassi

    Member
    December 5, 2014 at 6:46 pm

    I’ve solved this problem. I made another 1.5Kg test batch today. This time I increased the MEA to 2% and found that 2% Glucamate was very adequate, giving a syrup-like consistency. Perfectly clear, unlike when I tried the PEG-150 which even in small amounts gave a translucent shampoo.

    So, on to the next item.

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