Liquid Castor Oil Soap using Only Castor Oil
- Thread starter narayana
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ChemicalPyros
Member
Hello Narayana,
Usually for liquid soap, you start by making a paste, this paste is made of the reaction between the oil and KOH. KOH is made in a solution with water with a concentration of your choice, but usually it is between 25 and 40%.
The oil and KOH solution are mixed using a hand mixer, at first it gives a nice trace which usually separates, you should keep mixing at regular intervals till you notice an increase in viscosity, at this point stop mixing and wait, the process may take anywhere between 1 hour and 5 hours depending on the oils, the temperature and the KOH concentration.
Cover the mixture and leave it overnight for the reaction to complete. the next day you should have a sticky paste.
Dilute the paste in water (the amount of water to add depends on the final surfactant concentration you want). You should obtain a liquid that is not viscous. At this point you have 2 choices, if the liquid is opaque you can leave it a couple of days for it to separate, and you remove the top layer (which causes the opaqueness) then you thicken it, or you can thicken it directly. Thickening is done using cellulose polymers mainly, or salt when you have more than 50% oleic acid in the mixture.
As for your request to make the pH around 7, I highly recommend you do not try to decrease the pH since it will reverse the saponification and you will end up with oils instead of soap.
This is a very concise and general summary, if you have more specific questions, post them and I will be happy to help.
Usually for liquid soap, you start by making a paste, this paste is made of the reaction between the oil and KOH. KOH is made in a solution with water with a concentration of your choice, but usually it is between 25 and 40%.
The oil and KOH solution are mixed using a hand mixer, at first it gives a nice trace which usually separates, you should keep mixing at regular intervals till you notice an increase in viscosity, at this point stop mixing and wait, the process may take anywhere between 1 hour and 5 hours depending on the oils, the temperature and the KOH concentration.
Cover the mixture and leave it overnight for the reaction to complete. the next day you should have a sticky paste.
Dilute the paste in water (the amount of water to add depends on the final surfactant concentration you want). You should obtain a liquid that is not viscous. At this point you have 2 choices, if the liquid is opaque you can leave it a couple of days for it to separate, and you remove the top layer (which causes the opaqueness) then you thicken it, or you can thicken it directly. Thickening is done using cellulose polymers mainly, or salt when you have more than 50% oleic acid in the mixture.
As for your request to make the pH around 7, I highly recommend you do not try to decrease the pH since it will reverse the saponification and you will end up with oils instead of soap.
This is a very concise and general summary, if you have more specific questions, post them and I will be happy to help.
I think you’re looking at something non-soap, if you need a pH of 7. Soap is alkaline, as the actual definition of soap is the salts of fatty acids (made by adding alkalinity via lye).
