Chemistry Reference
In-Depth Information
viscosity of MWO at 40 and 100 1C was 33.8 and 7.3, respectively, which
are within the range reported for SB, CAN and other seed oils.
19
PHMWO
displayed a very high dynamic viscosity (
1000-fold relative to MWO) and
non-Newtonian behavior at 40 1C. At 70 1Corhighertemperatures,however,it
displayed Newtonian behavior.
16
The latter behavior confirms the strong
intermolecular hydrogen-bonding resulting in non-Newtonian behavior of
this compound at lower temperatures. Higher temperatures therefore,
thermally disrupt these intermolecular hydrogen-bonds freeing the molecules
to behave as a Newtonian fluid. Esterification similarly disrupts hydrogen-
bonding, hence, the dynamic viscosities of the esterified PHMWOs
decreased with increasing ester group chain length as: PHMWO44
AMWO4BMWO4VMWO. This trend was observed for data generated by
both viscometers and at all temperatures. Analogous observations of the
effect of branching on viscosity have been reported in branched poly-
saccharides,
17
and branched synthetic polymers.
20-23
B
10.3.2 Cold Flow
The PPs and CPs of MWO and its derivatives are summarized in Table 10.5
with PP values for SBO and CANO, and similar derivatives of SBO in-
cluded. PHMWO displayed a similar PP to hydroxyl soybean oil (HSBO),
which showed an improvement over SB. AMWO displayed a similar PP to
ASBO, which was worse than HSBO, PHMWO, and even SBO. BMWO and
VMWO displayed similar PP values to PHMWO. However, the PP of BSBO
(-3 1C) was identical to those of ASBO and AMWO but much higher than
that of BMWO (
18 1C). This result is clearly anomalous since almost all
SBO and MWO derivatives displayed similar PP values except for BMWO
and VMWO. The CP of PHMWO displayed a four-fold improvement upon
esterification. There were no effects of the ester group chemical structure
on the CP. The esterified PHMWO derivatives had CPs that were in the
range
25 to
28 1C.
Table 10.5 Low-temperature flow properties of soybean (SB)
and milkweed (MW) derivatives.
Oil
Pour Point/1C
Cloud Point/1C
Ref.
SBO
9
—
22
CANO
21
—
22
ESBO
3
—
25
18
HSBO
—
25
a
HMWO
15
7
ASBO
3
—
25
a
AMWO
3
25
BSBO
3
—
25
a
BMWO
18
30
a
VMWO
18
28
a
This work.
