Stearate vs. Isostearate

[Guest guest]

I've been looking over the list of emulsifiers in Maurice's wonderful

HLB calculator sheet, and I was wondering if there's some sort of

characteristic difference between " stearate " esters and " isostearate "

esters in terms of their physical properties.

For instance, both Sorbitan Stearate and Sorbitan Isostearate have HLBs

of 4.7. So what would be the difference between the two in practical

application?

And there are other " stearate " combo's too. Monostearate (aka

Stearate), Distearate, Sequistearate -- all having to do with the

number of stearic acid-related parts within in the molecule, right? Are

there common characteristics associated with an increase in these

numbers?

(And I'm sorry if this is a dumb question! I was noticing the pattern

in the names in Maurice's list, but I have no background in organic

chemistry to interpret what they mean...)

Elaine

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Elaine Benfatto (Cambridge, MA)

elaine@...

http://www.urbanspinner.com/

[Guest guest]

>For instance, both Sorbitan Stearate and Sorbitan Isostearate have HLBs

>of 4.7. So what would be the difference between the two in practical

>application?

Sorbitan Stearate is a solid and Sorbitan Isostearate is a liquid.

Depending on your formula, the physical state of your emulsfier(s)

could make a difference.

Availability or sourcing could/should be another issue or concern to

some formulators. Sorbitan Stearate is easily found.

>And there are other " stearate " combo's too. Monostearate (aka

>Stearate), Distearate, Sequistearate -- all having to do with the

>number of stearic acid-related parts within in the molecule, right? Are

>there common characteristics associated with an increase in these

>numbers?

As you know, HLB stands for Hydrophile-Lipophile Balance.

As you increase the lipophilic portion of the molecule, you lower the

HLB.

Glyceryl Stearate = 3.8

Glyceryl Distearate = 2.4

Glycol Stearate = 2.9

Glycol Distearate = 1

and as you increase the hydrophilic portion, you raise the HLB.

Ceteth-2 = 5.3

Ceteth-10 = 12.9

Ceteth-20 = 15.7

Glycol Stearate = 2.9

Glycol Distearate = 1

Laureth-4 = 9.7

Laureth-23 = 16.9

Oleth-2 = 4.9

Oleth-20 = 15.3

Maurice

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Maurice O. Hevey

Convergent Cosmetics, Inc.

http://www.ConvergentCosmetics.com

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