Chemistry Reference
In-Depth Information
Table 5.3 Physical properties of rosin based zwitterionic surfactants
δ
CMC
(25
°
C)
(mN/m)
CMC
(mol/L)
FP(0/5 min)
mm
Surfactants
EP min
KP (
°
C)
Z01
21.3
1.39×10
-3
—
—
—
Z02
31.91
3.16×10
-3
—
—
—
Z03
33.20
3.01×10
-3
—
—
—
Z04
25.79
2.56×10
-3
—
—
—
Z06
—
5.16×10
-3
88/81
13
—
Z07
53.25
9×10
-1
—
—
—
Z09
35.0
2.0×10
-3
150/90
1.5
<0
Z10
36.5
1.3×10
-3
130/60
2.0
<0
Data adapted from references [20, 35-37, 40]
Table 5.4
shows the physical properties of some rosin based nonionic surfactants.
The δ
CMC
of most anionic surfactants are near 40, and their CMC values are near
10
-3
mol/L. Rosin-based nonionic surfactants with different degree of polymerisation
were investigated in detail and the results showed that their CMC values were near
10
-4
mol/L and the δ
CMC
values were between 32-40 mN/m.
5.3.2 Phase Behaviour
The theoretical study of rosin-based surfactants has attracted little attention in
recent years. Compared with fatty acid as a hydrophobic group, the tricyclic
hydrophenanthrene structure may show different phase behaviour.
Persson and co-workers investigated [61] the phase behaviour of two rosin-
based nonionic surfactants, polyoxyethy1ene dehydroabietates (DeHAb(EtO))
with polyoxyethylene chains of 11 and 22, in water and decanol system (
Figure
5.1
). DeHAb(EtO)
11
is completely miscible with water but has a low capacity for
solubilisation of decanol. However, at DeHAb(EtO)
22
surfactant concentrations of
0-25%, the maximum solubilisation capacity for decanol represents a nearly constant
ratio between the amount of solubilisate and surfactant. The results showed that
the two rosin-based surfactants behave similarly to nonionic surfactants with a
hydrophobic aliphatic carbon chain and a polyethylene oxide chain as the hydrophilic
group. However, the acyclic surfactant has a good solubilising capacity for most
