Chemistry Reference
In-Depth Information
2. Branched-chain alkyl groups (C
8
-C
22
, internal substitution)
CH
3
ð
CH
2
Þ
n
C
ð
CH
3
Þ
H
ð
CH
2
Þ
m
CH
2
S
3. Unsaturated alkenyl chains such as those derived from vegetable oils
CH
2
Þ
n
CH
CH
3
ð
CH
ð
CH
2
Þ
m
S
4. Alkylbenzenes (C
8
-C
15
C
6
H
4
with various substitution patterns)
C
9
H
19
ð
C
6
H
4
Þ
S
5. Alkylnaphthalenes (alkyl R usually C
3
or greater)
R
n
C
10
H
ð
7
n
Þ
S
6. Fluoroalkyl groups (n
>
4, partially or completely fluorinated)
CF
3
ð
CF
2
Þ
n
S
7. Polydimethylsiloxanes
CH
3
ð
OSi
½
CH
3
2
O
Þ
n
S
8. Polyoxypropylene glycol derivatives
CH
3
CH
ð
OH
Þ
CH
2
O
ð
CH
ð
CH
3
Þ
CH
2
O
Þ
n
S
9. Biosurfactants
10. Derivatives of natural and synthetic polymers
With such a wide variety of structures available, it is not surprising that the selec-
tion of a suitable surfactant for a given application can become a significant pro-
blem in terms of making the best choice of material for a given application.
2.1.2. Making Choice
The chemical structure of a surfactant is not the only determining factor in choos-
ing between potential surfactant candidates for a given application. Economic,
energetic, ecological, regulatory, and aesthetic considerations, in addition to ques-
tions of chemical functionality, are becoming more and more important in surfac-
tant structure selection. Since most surfactants are used in formulations that include
other ingredients, the relative role of the surfactant must be evaluated along with its
physicochemical characteristics.
