Chemistry Reference
In-Depth Information
Because the sulfosuccinates and sulfosuccinamates have shown excellent wet-
ting, dispersing, emulsifying, and foaming properties, they have found a wide
variety of applications in industry. Their applications range from use in lubricating
oils, ink dispersions, mineral ore flotation, and oil emulsion breakers to stabilizers
for emulsion polymerizations and emulsifiers, and coating aids in photographic
products. Some members of this family have also found extensive use in shampoos,
toilet bars, and other cosmetics because of their low skin irritation, and for ingestion
as stool softeners.
2.4.2.5. Alkyl Glyceryl Ether Sulfonates
The alkyl glyceryl ether sulfonate class of surfactants, represented by the general
formula
CH
2
SO
3
M
þ
ROCH
2
CH
ð
OH
Þ
were first synthesized in Germany relatively early in the twentieth century. How-
ever, there are very few data published about their specific properties, other than
the information available in the patent and trade literature. An early patent
described the reaction of epichlorohydrin with a fatty alcohol to produce the
chloroether, which was subsequently treated with sodium sulfite to yield the desired
sulfonate salt:
ROH
þ
C
3
H
5
ClO
!
ROCH
2
CH
ð
OH
Þ
CH
2
Cl
ROCH
2
CHOHCH
2
SO
3
Na
þ
ROCH
2
CH
ð
OH
Þ
CH
2
Cl
þ
Na
2
SO
3
!
The specific details of the reaction pathways to these materials can be quite com-
plex, not in the chemistry involved, but in the conditions necessary to obtain a com-
mercially useful product and process. The major problems are control of the
formation of di- and higher ethers from the epichlorohydrin and the removal of
unreacted starting materials and byproducts from the final material.
Patent references to the alkyl glyceryl ether sulfonates describe them as effi-
cient wetting, foaming, and dispersing agents, with improved water solubility
and stability to acids and bases. The materials are, however, inherently more expen-
sive than most other sulfonates and therefore have not received a great deal of inter-
est in most high-volume, low-cost applications. They have found extensive use only
in specialty areas where the added cost for the specific advantages of such materials
can be tolerated.
2.4.2.6. Lignin Sulfonates
Lignin sulfonates are, technically, low-molecular-weight polymers containing a
witch's brew of primary and secondary alcohols, phenols, and carboxylic acid func-
tionalities. They are prepared by the sulfonation of lignin byproducts of pulp and
paper manufacture, followed by neutralization to the sodium, calcium, or ammo-
nium salt. The resulting materials are useful as dispersing agents for solids and
oil/water emulsions, and as stabilizers for aqueous dispersions of dyes, pesticides,
and cement. They are very inexpensive relative to other materials and are very
