Home Cosmetic Science Talk Formulating Carbomer, should I assume they started with 100%?

  • ketchito

    Member
    December 19, 2020 at 12:53 pm

    @sean9980 You can make a solution dissolving your 90% NaOH in enough water to get the 18% solution of NaOH. 

  • belassi

    Member
    December 19, 2020 at 3:54 pm

    It really is quite simple. Make two experiments. Assume they used 99% pure in (1) and 90% in (2). Measure the resulting pH and viscosity.

  • MarkBroussard

    Member
    December 19, 2020 at 6:37 pm

    @sean9980

    The purity of your NaOH is not really of any significance.  Of course, higher purity means less “contaminants” … but, for these purposes the issue is getting enough NaOH into the mix to raise the pH to the point where the Carbomer will gel.  It really does not matter if you use 90% NaOH, 99% NaOH, an 18% solution or a 25% solution as long as you raise the pH sufficiently for the Carbomer to activate and gel.

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