Sodium Cocoyl Isethionate solubilization problem

Tagged: sci, shampoo, sodium cocoyl isethionate, solubilization, surfactants

Hair

Sodium Cocoyl Isethionate solubilization problem

Posted by Nanda on February 23, 2016 at 6:25 pm

Hi everyone, I’m new here and I hope I perhaps can get your expertise on a problem I’ve encountered making a shampoo formula with SCI.

I’ve done this formula before and it was a success, but this weekend I tried it out again and it was a complete failure even though I did everything as the last time, so I’m guessing it might be a temperature issue since I live in Sweden and it’s winter here now. Anyway, if anyone here has tried formulating with SCI I would highly appreciate if you guys could help me troubleshoot this.

The formula is:

53% H2O
10% Cocamidopropyl betaine
10% Sodium cocoyl isethionate (with stearic acid)
5% Coco glucoside
10% Aloe vera juice
2% Glycerin
2% Hydrolyzed oat protein
2% Polyquaternium-7
2% Coco caprylate
2% Panthenol
0,5% Optiphen
1% Fragrance
1% Crothix

The issue here is the SCI mixed together with Cocamidopropyl betaine, I used a water bath and heated them and the rest of my water phase apart (exept for preservatives, fragrance, panthenol, polyquat and crothix). BUT the SCI simply won’t melt and solubilize.

I’ve read online that it has a melting point of 200 degrees celcius which is very high, I would say even for a regular stove so I’m guessing a water bath simply won’t do. When I mix the 2 phases together the SCI simply forms a film floating on top and won’t mix at all no matter how much I try to stir it in. I finally had to take the layer off the top and after that the Crothix didn’t work at all.

How do you guys use SCI, and how high do you usually heat it before it dissolves? I’m used to having water evaporate quickly even with a water bath so it scares me to just put it over a regular stove top.

I’ve also considered purchasing ACI (Ammonium cocoyl isethionate) which is more water soluble but I can’t seem to find any suppliers who have it available, so I would gladly also take any advice on where I could get some.

Thank you so much in advance for your help!

thebrain replied 8 years, 8 months ago 6 Members · 12 Replies
12 Replies

chemist1

Member
February 23, 2016 at 10:04 pm

Is there a reason that you are using SCI/Stearic Acid combo?

Try using just SCI. Pureact I 78 C is SCI that some in a nice, small noodle shape that will melt at 50-60C.
chemist1

Member
February 23, 2016 at 10:05 pm

Sorry, Puareact I 78C comes in a noodle not some.
David

Member
February 23, 2016 at 10:32 pm

Well if you are from Sweden,like me , try the Elfan® AT 84 G from akzo. It dissolves just fine when you heat it a bit. mvh/David
Nanda

Member
February 24, 2016 at 9:34 am

Chemist1: I got a hold of the SCI powder available at Gracefruit and it contains Stearic acid so thought it was worth mentioning. Stearic acid has a pretty low melting point though so I don’t know if this could be contributing to this issue. I wanted to purchase the powder thinking that it would solubilize easier than noodles/flakes.

David: Hej och tack för tipset! I’m a beginner formulator so I still purchase from suppliers such as Gracefruit/Soapkitchen so excuse me for lacking a bit of knowledge in ordering from bigger suppliers like Akzo, I can only find an option to request sample on the site so not really sure how to order a larger quantity, but I’ll look around!

Also, do you use a regular water bath in normal room temperature and there are no issues? In this case I need to try this SCI.
heraklit

Member
February 24, 2016 at 12:43 pm

My 85% SCI melts easily in water at about 50-60° C. SCI / stearic mix is used at syndet soaps usually.
thebrain

Member
February 24, 2016 at 1:53 pm

@Nanda: One of my shampoo formulas contains SCI, so I have some experience with it. I also live in an area with cold winter climate, and you’re on the right track believing this to be an issue with temperature. SCI is nearly insoluble in water, but agitation and heat will help. If you can get Elfan AT 84G, it’s more soluble in water at low(er) temperatures, but you need to keep it below 60C during processing. I ran a whole bunch of tests to determine the solubility of SCI in various surfactants. As a rough estimate, I think the solubility of SCI in betaine is 1:3. Thus, if you want to use 10% SCI, you will need 30% betaine to do it. Any less than this and it will eventually separate. If you’re unsure whether your formulation is stable, try doing some freeze/thaw tests in your freezer. HTH!
Nanda

Member
February 25, 2016 at 5:04 pm

thebrain: Thank you! I’ll try formulating a test batch with 30% cocamidopropyl betaine and 10% SCI and see how it goes. Does your mix turn completely clear when dissolved or does it look white/cloudy? I’m just wondering for reference, it’s been such a long time since I did this formula so I’m not really sure what it should look like when completely melted.
thebrain

Member
February 25, 2016 at 9:07 pm

@Nanda: If I use the right ratio, it remains stable and completely clear even if I store it in my refrigerator.
hasanarsan

Member
February 26, 2016 at 6:50 am

Hope this linl would help you.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.574.2046&rep=rep1&type=pdf
Best regards
Hasan
hasanarsan

Member
February 26, 2016 at 7:29 am

Dear Nanda,
Ammonium Cocoyl Isethionate is the one which is soluable in water. It usually supplied %30 solution form. Jordapon ACL 30 can be one example for this.
Hope would help.
Regards
Hasan
Nanda

Member
March 2, 2016 at 8:56 pm

hasanarsan: Thank you!

thebrain: Amazing, I did 30% cocamidopropyl betaine and 10% SCI and it worked like a charm. It was a little tricky to dissolve into the water phase but stick blending did the trick (and not much foam due to blending either, thank goodness). So thank you so much!
thebrain

Member
March 4, 2016 at 1:54 pm

@Nanda: I’m glad it worked out for you You’re welcome.