How CTAC contribute to the viscosity?

Formulating

How CTAC contribute to the viscosity?

Posted by ZivBA on August 16, 2018 at 5:56 am
Hello,

I have a formula for hair cream according to the following raw materials:

Phase 1, Heating to 70:
1. Water- 80%
2. Polyquaternium7- 2%
Phase 2, Heating to 70:
1. Mineral Oil- 5%
2. Cetyl Alcohol- 4%
3. GMS SE- 2%
4. Dimethicone 350cp- 1%
5. Vaseline- 1%
Homogenize and stirring.

Then the liquid product is liquid at 50-60 temp,
But immediately with the addition of CTAC-4%, the substance becomes a viscous cream.

why?
DAS replied 6 years, 9 months ago 5 Members · 11 Replies
11 Replies

ozgirl

Member
August 16, 2018 at 10:58 am

It is most likely that the CTAC (cationic) is incompatible with the anionic potassium stearate that is present in the GMS SE.
Gunther

Member
August 16, 2018 at 9:57 pm

Usually CETAC reduces viscosity
But you can try mixing some bare K-stearate with CETAC to see if they form a thick slime = sign of uncompatibility.
DrAndrewWorthen

Member
August 17, 2018 at 12:46 am

Also, this effect would likely be pH dependent, where it would be less significant below the pKa of the potassium stearate (i.e., where it becomes neutral).
ZivBA

Member
August 19, 2018 at 5:08 am

Thank you for the comments,

I want to say that this change to thick cream is welcome! I want and need this change, I just still don’t understand how and why it is happening, and what I should do if I want to duplicate it to another formula

you all say that the small amount of K-Stearate that is present in the GMS SE is responsible for this change?
DAS

Member
August 19, 2018 at 10:04 pm

It’s how an ewax is made. Cetyl + surfactant, in this case the CTAC.
ZivBA

Member
August 22, 2018 at 6:25 am

DAS - sorry for the dam question-

What is EWAX, and how it is made?
DAS

Member
August 22, 2018 at 9:57 pm

Self emulsifying waxes are a blend of a fatty alcohol and a surfactant. The result is usually a solid, for example BTMS is an ewax. It becomes pasty even at low percentage. Considering you are using 4% of each the result will be creamy on cool down. The reticulate formed by the cetyl alcohol + CTAC is what holds the rest of the ingredients. You do have an important quantity of oils, the GMS SE wouldn’t hold by itself.
ZivBA

Member
August 27, 2018 at 7:06 am

DAS- Thank You Very Much!!!!!

In your opinion- Should I add the CTAC at the END of the procedure at cool down, Or should I add it with the water phase at the first stage?
DAS

Member
August 27, 2018 at 11:26 am

First stage. Better homogenization with less torque, and to prevent air bubbles.
Gunther

Member
August 28, 2018 at 8:04 pm

Interesting
I always wondered if you can make an emulsifier out of CETAC + fatty alcohol.

@DAS Do you know why Croda used cetyl alcohol in their BTMS and not cetearyl alcohol instead?
DAS

Member
August 29, 2018 at 5:22 am

It IS an emulsion. Think of you hair conditioners, what would happen if you remove the surfactant?.

You would have to ask croda, perhaps if you mail R&D they answer. They do perform differently, those 2 carbons make a huge difference. Cetearyl is used to avoid recrystallization (being 16 and 18 they don’t align the same). Perhaps the microstructure with BTMS shows no significant difference.