Sorbitol is a white, sweetish, hygroscopic, crystalline sugar alcohol of
six-carbon. It is found naturally in various berries and fruits. Or it is
prepared synthetically by high-pressure catalytic hydrogenation of glucose sugar
derived from cornstarch. It melts at 93 to 98 C depending on the form. It is
used as a a sweetening agent, food additive, toothpaste, tobacco, toiletries and
in cosmetics. It is used for vitamin-C fermentation. It is used as a excipient
and intravenous osmotic diuretic in pharmaceutical fields. It is also used in
the manufacture of polyethers for polyurethanes and surfactants. The term
sorbitan describes the anhydride form of sorbitol, whose fatty acids are
lipophilic whereas sorbitol body is hydrophilic. This bifunctionality in one
molecule provides the basic properties useful in cleaners, detergents, polymer
additives, and textile industry as emulsifiers, wetting agents, and viscosity
modifiers. Sorbitan esters are rather lipophilic (or hydrophobic) surfactants
exhibiting low HLB (Hydrophilic-Lipophilic Balance) values; having an affinity
for, tending to combine with, or capable of dissolving in lipids (or
water-insoluble). While, the ethoxylated sorbitan esters are hydrophilics
exhibiting high HLB values; having an affinity for water; readily absorbing or
dissolving in water. The type of fatty acid and the mole number of ethylene
oxide provides diverse HLB values for proper applications.
HLB numbers
describe following characterestics:
<10 : Lipid soluble (or
water-insoluble) >10 : Water Soluble 4-8 : Antifoaming 7-11 :
Water-in-oil emulsion 12-16 : Oil-in-water emulsion 11-14 : Good
Wetting 12-15 : Good detergency 16-20 : Stabilizing
HLB values of
sorbitan compounds are:
Surfactants
|
HLB
Value
|
CAS
RN
|
Sorbitan hexastearate ethoxylate EO 6 mole |
3.0
|
|
Sorbitan isostearate
|
4.3
|
|
Sorbitan laurate
|
8.6
|
1338-39-2 |
Sorbitan monoisostearate ethoxylate EO 20 mole |
15.0
|
66794-58-9 |
Sorbitan monolaurate ethoxylate EO 20 mole |
16.9
|
9005-64-5 |
Sorbitan monooleate ethoxylate EO 20 mole |
15.0
|
9005-65-6 |
Sorbitan monopalmitate ethoxylate EO 20 mole |
15.6
|
9005-66-7 |
Sorbitan monostearate ethoxylate EO 20 mole |
14.9
|
9005-67-8 |
Sorbitan monstearate ethoxylate EO 6 mole |
9.5
|
|
Sorbitan oleate
|
4.3
|
1338-43-8 |
Sorbitan palmitate
|
6.7
|
26266-57-9
|
Sorbitan sesquioleate
|
4.5
|
8007-43-0 |
Sorbitan stearate
|
4.7
|
1338-41-6 |
Sorbitan tetraoleate ethoxylate EO 30 mole |
11.5
|
|
Sorbitan tetraoleate ethoxylate EO 40 mole |
12.5
|
|
Sorbitan tetraoleate ethoxylate EO 6 mole |
8.5
|
63089-86-1 |
Sorbitan tetrastearate ethoxylate EO 60 mole |
13.0
|
66828-20-4 |
Sorbitan trioleate ethoxylate EO 20 mole |
11.0
|
9005-70-3 |
Sorbitan trioleate
|
1.8
|
26266-58-0 |
Sorbitan tristearate ethoxylate EO 20 mole |
10.5
|
9005-71-4 |
Sorbitan tristearate
|
2.1
|
26658-19-5 |
|