Calculating HLB Values

[Guest guest]

>So Maurice, how do you determine the ratio of the emulsifiers, the high HLB

>to the low HLB. This is a subject where we need the other installments if

>you have the time to put them together. How about % or is that just trial

>and error?

First, you should know that the HLB System is a tool; not a rule. It's

not an easy short cut to the perfect emulsion. The HLB System

dramatically simplifies the choice of surfactants necessary to meet

emulsion formulation requirements. It is based on the balance between

the hydrophilic and the lipophilic proportions that give each

surfactant its functionality.

It is a tool that will guide you in the right direction.

In 1949, C. (Bill) developed the Hydrophile-Lipophile

Balance System or HLB System when he was a chemist at the Atlas Powder

Company, which eventually became ICI Surfactants.

All emulsifier have two parts. In many ways, similar to a bar magnet.

A bar magnet has a north pole and a south pole. Nonionic emulsifiers

also have two poles or parts.

An emulsifier molecule has one part that loves water and one part loves

oil. The water loving part is called hydrophilic; " hydro-` meaning

water and " -philic " meaning to love or like.

The other part of the emulsifier molecule is lipophilic; If " lipo- "

means fat or oil, then lipophilic means oil loving.

Therefore, an emulsifier has a hydrophilic part and a lipophilic part.

The balance of these two portions of the emulsifier gives us the

Hydrophile-Lipophile Balance (HLB). The HLB of emulsifiers can be

calculated or determined through trial and error.

According to the HLB System, all fats and oils have a Required HLB.

Listed below are the Required HLBs for a few oils:

The Required HLB for Stearyl Alcohol is 15.5

The Required HLB for Cetyl Alcohol is 15.5

The Required HLB for Jojoba Oil is 6 to 7

The Required HLB for Peanut Oil is 5.5

The Required HLB for Cotton Seed Oil is 6

The Required HLB for Vitamin E is 6

The Required HLB for Isopropyl Palmitate is 12

The Required HLB for Beeswax is 12

Most homecrafters seem to use vegetable oils. Vegetable oils have a

Required HLB that ranges from 5.5 to 7.5.

According to the HLB System, to emulsify an oil into water, you must

use an emulsifier that matches the Required HLB of the oil.

So if you emulsify an oil that has a Required HLB of 6, you will need

an emulsifier or blend of emulsifiers that have a HLB of 6.

Here is a list of commonly used emulsifiers, sorted by HLB:

Gycol Distearate (HLB = 1)

Sorbitan Trioleate (HLB = 1.8)

Glycol Stearate (HLB = 2)

Glyceryl Stearate (HLB = 3.6)

Sorbitan Sesquioleate (HLB = 3.7)

Sorbitan Oleate (HLB = 4.3)

Methyl Glucose Dioleate (HLB = 4.4)

Sorbitan Stearate (HLB = 4.7)

Oleth-2 (HLB = 4.9)

Steareth-2 (HLB = 4.9)

Ceteth-2 (HLB = 5.3)

Glyceryl Stearate SE (HLB = 5.8)

PEG-4 Dilaurate (HLB = 6)

Methyl Glucose Sesquistearate (HLB = 6.6)

Sorbitan te (HLB = 8.6)

PEG-40 Sorbitan Peroleate (HLB = 9)

Laureth-4 (HLB = 9.7)

Glyceryl Stearate (and) PEG-100 Stearate (HLB = 11)

Polysorbate 85 (HLB = 11)

Oleth-10 (HLB = 12.4)

Oleth-20 (HLB = 12.4)

Ceteth-10 (HLB = 12.9)

PEG-8 te (HLB = 13)

Polysorbate 60 (HLB = 14.9)

Isosteareth-20 (HLB = 15)

PEG-20 Methyl Glucose Sesquistearate (HLB = 15)

Polysorbate 80 (HLB = 15)

Ceteareth-20 (HLB = 15.2)

Oleth-20 (HLB = 15.3)

Steareth-20 (HLB = 15.3)

Steareth-21 (HLB = 15.5)

Ceteareth-20 (HLB = 15.7)

Ceteth-20 (HLB = 15.7)

Ceteth-20 (HLB = 15.7)

Isoceteth-20 (HLB = 15.7)

Polysorbate 20 (HLB = 16.7)

Laureth-23 (HLB = 16.9)

PEG-100 Stearate (HLB = 18.8)

PEG-80 Sorbitan te (HLB = 19.1)

So, to emulsify Jojoba Oil which has a required HLB of 6 to 7, we need

an emulsifier or blend of emulsifiers that will have a HLB of 6 to 7.

So if this is the case, we could use Glyceryl Stearate SE (HLB = 5.8),

PEG-4 Dilaurate (HLB = 6) or Methyl Glucose Sesquistearate (HLB = 6.6)

to emulsify Jojoba Oil into water.

However, numerous experiments have demonstrated that blends of

emulsifiers generally produce more stable emulsions when compared to

emulsions formed with a single emulsifier. This is why blending

emulsifiers is important.

Let looks at blending emulsifiers. For the purposes of this example,

lets use Sorbitan Oleate and Polysorbate 80. From the list above, we

can see that Sorbitan Oleate has a HLB of 4.3 and Polysorbate 80 has a

HLB of 15.

Intuitively, we know that we use only Sorbitan Oleate the HLB will be

4.3 and if we use only Polysorbate 80, the HLB will be 15.

But what would the HLB if we were to use an emulsifier blend of 50%

Sorbitan Oleate and 50% Polysorbate 80?

Well 50% of the HLB would come from the Sorbitan Oleate and the

remaining 50% would come from the Polysorbate 80.

So we have

HLB = (50% x 4.3) + (50% x 15)

HLB = (.5 x 4.3) + (.5 x 15)

HLB = 2.15 + 7.5

HLB = 9.65 or rounding off, we have HLB = 9.7

Let's try another example. This time, let's assume we are blending 75%

Sorbitan Oleate with 25% Polysorbate 80.

HLB = (25% x 4.3) + (75% x 15)

HLB = (0.25 x 4.3) + (0.75 x 15)

HLB = 1.1 + 11.3

HLB = 12.4

So we can see a general formula developing.

Let's say we are working with two different emulsifiers, Emulsifier X

and Emulsifier Y.

The HLB of Emulsifier X is HLBx and the HLB of Emulsifier Y is HLBy.

Then the HLB of any combination of these two emulsifiers can be written

as:

HLB = (X% x HLBx) + (Y% x HLBy)

Using this formula, you can calculate the HLB of any emulsifier blend.

Using the blend of Sorbitan Oleate and Polysorbate 80, we can now

calculate the HLBs of any blend.

0% Sorbitan Oleate + 100% Polysorbate 80 = HLB 15

5% Sorbitan Oleate + 95% Polysorbate 80 = HLB 14.5

10% Sorbitan Oleate + 90% Polysorbate 80 = HLB 13.9

15% Sorbitan Oleate + 85% Polysorbate 80 = HLB 13.4

20% Sorbitan Oleate + 80% Polysorbate 80 = HLB 12.9

25% Sorbitan Oleate + 75% Polysorbate 80 = HLB 12.3

30% Sorbitan Oleate + 70% Polysorbate 80 = HLB 11.8

35% Sorbitan Oleate + 65% Polysorbate 80 = HLB 11.3

40% Sorbitan Oleate + 60% Polysorbate 80 = HLB 10.7

45% Sorbitan Oleate + 55% Polysorbate 80 = HLB 10.2

50% Sorbitan Oleate + 50% Polysorbate 80 = HLB 9.7

55% Sorbitan Oleate + 45% Polysorbate 80 = HLB 9.1

60% Sorbitan Oleate + 40% Polysorbate 80 = HLB 8.6

65% Sorbitan Oleate + 35% Polysorbate 80 = HLB 8

70% Sorbitan Oleate + 30% Polysorbate 80 = HLB 7.5

75% Sorbitan Oleate + 25% Polysorbate 80 = HLB 7

80% Sorbitan Oleate + 20% Polysorbate 80 = HLB 6.4

85% Sorbitan Oleate + 15% Polysorbate 80 = HLB 5.9

90% Sorbitan Oleate + 10% Polysorbate 80 = HLB 5.4

95% Sorbitan Oleate + 5% Polysorbate 80 = HLB 4.8

100% Sorbitan Oleate + 0% Polysorbate 80 = HLB 4.3

From this we can see that

75% Sorbitan Oleate + 25% Polysorbate 80 = HLB 7

80% Sorbitan Oleate + 20% Polysorbate 80 = HLB 6.4

85% Sorbitan Oleate + 15% Polysorbate 80 = HLB 5.9

could be used to emulsify Jojoba Oil into water.

Let's look at another blend of emulsifiers. This time, let's use

Steareth-2 (HLB 4.9) and Steareth-21 (HLB 15.5).

Using the formula from above, we can generate the following range of

HLBs:

0% Steareth-2 + 100% Steareth-21 = HLB 15.5

5% Steareth-2 + 95% Steareth-21 = HLB 15

10% Steareth-2 + 90% Steareth-21 = HLB 14.4

15% Steareth-2 + 85% Steareth-21 = HLB 13.9

20% Steareth-2 + 80% Steareth-21 = HLB 13.4

25% Steareth-2 + 75% Steareth-21 = HLB 12.9

30% Steareth-2 + 70% Steareth-21 = HLB 12.3

35% Steareth-2 + 65% Steareth-21 = HLB 11.8

40% Steareth-2 + 60% Steareth-21 = HLB 11.3

45% Steareth-2 + 55% Steareth-21 = HLB 10.7

50% Steareth-2 + 50% Steareth-21 = HLB 10.2

55% Steareth-2 + 45% Steareth-21 = HLB 9.7

60% Steareth-2 + 40% Steareth-21 = HLB 9.1

65% Steareth-2 + 35% Steareth-21 = HLB 8.6

70% Steareth-2 + 30% Steareth-21 = HLB 8.1

75% Steareth-2 + 25% Steareth-21 = HLB 7.6

80% Steareth-2 + 20% Steareth-21 = HLB 7

85% Steareth-2 + 15% Steareth-21 = HLB 6.5

90% Steareth-2 + 10% Steareth-21 = HLB 6

95% Steareth-2 + 5% Steareth-21 = HLB 5.4

100% Steareth-2 + 0% Steareth-21 = HLB 4.9

So, if we wanted to emulsify our Jojoba Oil into water, we would use

one of these blends:

80% Steareth-2 + 20% Steareth-21 = HLB 7

85% Steareth-2 + 15% Steareth-21 = HLB 6.5

90% Steareth-2 + 10% Steareth-21 = HLB 6

For more information on this blend of emulsifiers and some different

formulations using blends of these emulsifiers, I suggest you go to:

http://www.uniqema.com/pc/pc17.pdf

Pat, I hope this information answers some of your questions.

Maurice

------------------------

Maurice O. Hevey

Convergent Cosmetics, Inc.

http://www.ConvergentCosmetics.com