Note: Descriptions are shown in the official language in which they were submitted.
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AIRCRAFT DEICING/ANTI-ICING FLUID THICKENED BY ALKYL
ALKANOLAMINE SURFACTANT, AND PREPARATION METHOD
THEREOF
TECHNICAL FIELD
The present invention relates to the field of deicing and anti-icing, and in
particular,
relates to a deicing/anti-icing fluid used for the outer surface of an
aircraft, and a
preparation method thereof.
BACKGROUND
In cold and humid air, it is common to find accumulation of ice and/or snow on
the
surface of a parked aircraft. The added ice or snow increases the weight of
the aircraft,
roughens the surface of the aircraft, which causes an increased drag and
reduces the
lifting force during take off. This tends to cause flight accidents, posing a
serious threat
to flight safety. Therefore, as specified in international aviation standards,
the
accumulated ice and snow on the surface of an aircraft must be removed before
the
aircraft takes off. A variety of deicing methods have been developed for
removing the
ice and snow that are accumulated on aircraft surface, such as mechanical
deicing,
electric heating deicing, and application of anti-icing materials. Currently,
using an
aircraft deicing fluid, especially non-Newtonian deicing/anti-icing fluid, is
the most
widely-used and effective way. In addition to effectively remove the
accumulated ice
and snow on the surface of an aircraft, Non-Newtonian deicing/anti-icing fluid
also
prevent the surface of the aircraft from being frozen within a certain period
of time.
Presently, in international aviation, a non-Newtonian deicing/anti-icing fluid
is
generally prepared by thickening a mixture of alcohol/water with water-soluble
polymers, including synthetic polymers and natural polymers, e.g., polyacrylic
acid
(PAA) and derivatives thereof, xanthan gum, guar gum and cellulose. Although
the
deicing/anti-icing fluid that are sprayed on the surface of an aircraft, would
mostly
likely be blown off when the aircraft undergoes high-speed flight, a small
amount will
remain on the aircraft, some relatively-hidden in the areas of wings and
elevators. These
residual polymer liquids easily form hydrogels, thereby causing hidden
troubles to the
flight safety. Moreover, the existing deicing/anti-icing fluids usually
undergo high-
speed shearing during the preparation, transportation, and operation, which
results in a
certain degree of degradation of polymer molecular chains, thereby reducing
the
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performance of the deicing/anti-icing fluid.
Remarkably reducing or even avoiding the use of polymers in aircraft
deicing/anti-
icing fluids is an effective way to solve the above problems. Chinese patent
CN105199671A discloses an anti-icing fluid thickened by an oligomeric cationic
surfactant and a preparation method to obtain an anti-icing fluid based on an
oligomeric
cationic surfactant. However, the cationic surfactant used can increase the
viscosity to
obtain a non-Newtonian anti-icing fluid described above only works at high
concentration and under the addition of inorganic or organic salts. The
addition of salts
tremendously increases the potential risk of corrosion on the surface of an
object, and
tends to cause the instability of the anti-icing fluid system, thereby
compromising the
safety of use. Chinese patent CN106883819A discloses "a deicing/anti-icing
fluid
based on an ultra-long-chain viscoelastic surfactant and a preparation method
thereof',
where an aircraft deicing/anti-icing fluid thickened by an ultra-long-chain
surfactant is
obtained. However, it requires the surfactant to be synthesized artificially
using a
complicated preparation process, and calls for an expensive raw material,
namely, an
ultra-long-chain organic acid. In addition, the surfactant needs to be used at
a high
concentration, which further increases the cost of the deicing/anti-icing
fluid.
SUMMARY
The present invention is intended to provide an aircraft deicing/anti-icing
fluid
thickened by an alkyl alkanolamine surfactant and a preparation method thereof
in view
of the shortcomings of the prior art, which can overcome the problem that
conventional
deicing/anti-icing fluids are prone to form hydrogels on the surface of an
aircraft and
cause corrosion on the surface of an aircraft. The deicing/anti-icing fluid of
the present
invention has the advantages of stable performance while requires simple
preparation
and low cost.
The present invention provides an aircraft deicing/anti-icing fluid thickened
by an
alkyl alkanolamine surfactant, including the following components, in mass
percentage:
27% to 66% of alcohol, 32% to 72% of deionized water, and 0.4% to 2.0% of
surfactant.
The surfactant is at least one of alkyl alkanolamine surfactants with a
structure having
the following general formula.
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(C1-12)pCI-13
,N,
HOn(H2C)- '(CH2601.-1
In the general formula, n is 1 to 5; m is 1 to 5; p is 15 to 21; and n, m and
p are all integers.
In the above technical solution of the present invention, the alkyl
alkanolamine surfactant
is preferably N-octadecyl diethanolamine.
In the above technical solution of the present invention, the alcohol is at
least one of alkyl
diol with 2 to 5 carbon atoms and alkyl polyol with 2 to 5 carbon atoms. The
alkyl diol is
preferably ethylene glycol, 1, 2-propylene glycol or 1,3-propylene glycol; and
the alkyl polyol
is glycerol.
The present invention provides a deicing/anti-icing fluid used by aircrafts
that is thickened
by an alkyl alkanolamine surfactant, preferably including the following
components, in mass
percentage: 29% to 65% of alcohol, 34% to 70% of deionized water, and 0.4% to
1.5% of alkyl
alkanolamine surfactant.
The present invention provides a method for preparing the deicing/anti-icing
fluid thickened
by an alkyl alkanolamine surfactant described above, including: mixing
deionized water and
alcohol, and thoroughly stirring the resulting mixture; and adding an alkyl
alkanolamine
surfactant at room temperature, and stiffing the resulting mixture until the
surfactant is
completely dissolved.
In the present invention, the surfactants are all existing compounds, which
are commercially
available.
The present invention has the following beneficial effects comparing to the
prior art.
1. The surfactant in the deicing/anti-icing fluid of present invention is
commercially
available, and because it is a nonionic surfactant without any ionic head
group in the molecular
structure, it does not corrode metals, plastics and the like, and it is safe
to use.
2. The deicing/anti-icing fluid of the present invention requires a low
concentration
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of surfactant, resulting in low cost.
3. The deicing/anti-icing fluid of the present invention does not include
polymers,
which effectively reduce the risk of forming hydrogel.
4. The freezing point of the deicing/anti-icing fluid of the present invention
can be
adjusted by adjusting the ratio of alcohol to water, and the minimum freezing
point can
reach -51.0 C, leading to a wide application range.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.47 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/ethylene glycol at different temperatures according to Example 5.
FIG. 2 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.44 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/glycerol at different temperatures according to Example 6.
FIG. 3 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.90 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/glycerol at different temperatures according to Example 7.
FIG. 4 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.88 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/glycerol at different temperatures according to Example 8.
FIG. 5 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.66 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/glycerol at different temperatures according to Example 9.
FIG. 6 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 1.31 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/glycerol at different temperatures according to Example 10.
FIG. 7 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.49 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/l, 2-propylene glycol at different temperatures according to Example 11.
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FIG. 8 is a graph illustrating the relationship between the shear rate and the
viscosity of the solution of 0.49 wt% N-octadecyl diethanolamine in a mixed
solvent of
water/1,3-propylene glycol at different temperatures according to Example 12.
FIG. 9 shows the anti-icing effect of the deicing/anti-icing fluid composed of
0.44
wt% N-octadecyl diethanolamine and water/glycerol on an aluminum substrate
(a), a
glass substrate (b), and a plastic substrate (c) according to Example 13.
DETAILED DESCRIPTION
The deicing/anti-icing fluid thickened by an alkyl alkanolamine surfactant and
the
preparation method thereof disclosed in the present invention is further
described below
through examples.
In the following examples, the surfactants and alcohols used are all available
at
reagent companies on the market.
Example 1
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 47.05
Alcohol: Ethylene glycol 52.48
Surfactant: N-octadecyl diethanolamine 0.47
Preparation: Adding Ethylene glycol to deionized water at room temperature
according
to the amount in the formula, add N-octadecyl diethanolamine, stir the
resulting mixture
until the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-
icing fluid.
As measured according to Petrochemical Industry Standard of the People's
Republic of China (SH/T 0090-91), this deicing/anti-icing fluid has a freezing
point of
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-40.3 C, indicating that the deicing/anti-icing fluid of the present invention
has a
relatively-low freezing point and can work in most extremely-cold
environments.
Example 2
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 48.90
Alcohol: 1, 2-propylene glycol 50.61
Surfactant: /V-octadecyl di ethanol amine 0.49
Preparation: adding 1, 2-propylene glycol to deionized water at room
temperature
according to the amount in the formula, add N-octadecyl diethanolamine, stir
the
resulting mixture until the N-octadecyl diethanolamine is completely dissolved
to
obtain a deicing/anti-icing fluid.
As measured according to Petrochemical Industry Standard of the People's
Republic of China (SH/T 0090-91), this deicing/anti-icing fluid has a freezing
point of
-36.6 C, indicating that the deicing/anti-icing fluid of the present invention
has a
relatively-low freezing point and can work in most extremely-cold
environments.
Example 3
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 48.54
Alcohol: 1,3-propylene glycol 50.97
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Surfactant: N-octadecyl diethanolamine 0.49
Preparation: adding 1,3-propylene glycol to deionized water at room
temperature
according to the amount in the formula, add N-octadecyl diethanolamine, stir
the
resulting mixture until the N-octadecyl diethanolamine is completely dissolved
to
obtain a deicing/anti-icing fluid.
As measured according to Petrochemical Industry Standard of the People's
Republic of China (SH/T 0090-91), this deicing/anti-icing fluid has a freezing
point of
-30.4 C, indicating that the deicing/anti-icing fluid of the present invention
has a
relatively-low freezing point and can work in most extremely-cold
environments.
Example 4
In this example, four deicing/anti-icing fluid are prepared according to the
following formulas:
Component Parts by mass (100 parts in total)
Deionized water 69.72 53.80 43.80 34.25
Alcohol: Glycerol 29.35 45.30 55.32 64.89
Surfactant: N-octadecyl diethanolamine 0.93 0.90 0.88 0.86
Preparation: adding Glycerol to deionized water at room temperature according
to
the amount in each formula, add N-octadecyl diethanolamine according to the
amount
in each formula, stir the resulting mixtures separately until the N-octadecyl
diethanolamine was completely dissolved to obtain deicing/anti-icing fluids.
As measured according to Petrochemical Industry Standard of the People's
Republic of China (SH/T 0090-91), the above four deicing/anti-icing fluids
have
freezing points of -9.5 C, -21.0 C, -31.8 C and -51.0 C, respectively, which
indicates
that the freezing point of the deicing/anti-icing fluid of the present
invention can be
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adjusted to meet the requirements of use in most environments.
Example 5
In this example, the components of the deicing/anti-icing fluid, the content
of each
component, and the preparation method were the same as those in Example 1.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship between the apparent viscosity of the deicing/anti-icing fluid
and the shear
rate at -20 C, -10 C, 0 C, 10 C, and 20 C. As shown in FIG. 1, the
deicing/anti-icing
fluid exhibits a higher apparent viscosity under a low shear rate, and as the
shear rate
increases, the viscosity decreases significantly. Thus, the deicing/anti-icing
fluid
shows an obvious shear-thinning behavior, which is consistent with the
rheological
behavior of a non-Newtonian deicing/anti-icing fluid. In addition, the zero-
shear
viscosity of the deicing/anti-icing fluid increases as the temperature
decreases,
and the viscosity is greater at a low temperature, making the deicing/anti-
icing
fluid suitable for low-temperature environments.
Example 6
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 43.99
Alcohol: Glycerol 55.57
Surfactant: N-octadecyl diethanolamine 0.44
Preparation: adding Glycerol to deionized water at room temperature according
to
the amount in the formula, add N-octadecyl diethanolamine, stir the resulting
mixture
until the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-
icing fluid.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship
between the apparent viscosity and the shear rate at -20 C, 0 C, and 20 C. As
shown
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in FIG. 2, the fluid exhibits a higher apparent viscosity under a low shear
rate, and as
the shear rate increases, the viscosity decreases significantly. Thus, the
fluid shows an
obvious shear-thinning behavior, which is consistent with the theological
behavior of a
non-Newtonian deicing/anti-icing fluid. Moreover, the zero-shear viscosity of
the
deicing/anti-icing fluid significantly increases as the temperature decreases,
and the
viscosity is greater at a low temperature, making the deicing/anti-icing fluid
suitable
for low-temperature environments.
Example 7
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 53.80
Alcohol: Glycerol 45.30
Surfactant: N-octadecyl diethanolamine 0.90
Preparation: adding Glycerol to deionized water at room temperature according
to
the amount in the formula, add N-octadecyl diethanolamine, and stir resulting
mixture
until the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-
icing fluid.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship between the apparent viscosity and the shear rate at -20 C, 0 C,
and 20
C. As shown in FIG. 3, the fluid exhibits a higher apparent viscosity under a
low
shear rate, and as the shear rate increases, the viscosity decreases
significantly. Thus,
the fluid shows an obvious shear-thinning behavior, which is consistent with
the
rheological behavior of a non-Newtonian deicing/anti-icing fluid. Moreover,
the
zero-shear viscosity of the deicing/anti-icing fluid significantly increases
as the
temperature decreases, and the viscosity is greater at a low temperature,
making the
deicing/anti-icing fluid suitable for low-temperature environments.
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Example 8
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 43.80
Alcohol: Glycerol 55.32
Surfactant: N-octadecyl diethanolamine 0.88
Preparation: adding Glycerol to deionized water at room temperature according
to
the amount in the formula, add N-octadecyl diethanolamine, stir the resulting
mixture
until the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-
icing fluid.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship between the apparent viscosity and the shear rate at -20 C, 0 C,
and 20
C. As shown in FIG. 4, the fluid exhibits a higher apparent viscosity under a
low
shear rate, and as the shear rate increases, the viscosity decreases
significantly. Thus,
the fluid shows an obvious shear-thinning behavior, which is consistent with
the
rheological behavior of a non-Newtonian deicing/anti-icing fluid. Moreover,
the
zero-shear viscosity of the deicing/anti-icing fluid significantly increases
as the
temperature decreases, and the viscosity is greater at a low temperature,
making the
deicing/anti-icing fluid suitable for low-temperature environments.
Example 9
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
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Deionized water 43.90
Alcohol: Glycerol 55.44
Surfactant: N-octadecyl diethanolamine 0.66
Preparation: adding Glycerol to deionized water at room temperature according
to
the amount in the formula, add N-octadecyl diethanolamine, stir the resulting
mixture
until the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-
icing fluid.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship between the apparent viscosity and the shear rate at -20 C, 0 C,
and 20
C. As shown in FIG. 5, the fluid exhibits a higher apparent viscosity under a
low
shear rate, and as the shear rate increases, the viscosity decreases
significantly. Thus,
the fluid shows an obvious shear-thinning behavior, which is consistent with
the
rheological behavior of a non-Newtonian deicing/anti-icing fluid. Moreover,
the
zero-shear viscosity of the deicing/anti-icing fluid significantly increases
as the
temperature decreases, and the viscosity is greater at a low temperature,
making the
deicing/anti-icing fluid suitable for low-temperature environments.
Example 10
In this example, a deicing/anti-icing fluid is prepared according to the
following
formula:
Component Parts by mass (100 parts in total)
Deionized water 43.61
Alcohol: Glycerol 55.08
Surfactant: N-octadecyl diethanolamine 1.31
Preparation: adding Glycerol to deionized water at room temperature according
to
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the amount in the formula, add N-octadecyl diethanolamine, stir resulting
mixture until
the N-octadecyl diethanolamine is completely dissolved to obtain a
deicing/anti-icing
fluid.
A rotational rheometer (Anton Paar, MCR 302) is used to determine the
relationship between the apparent viscosity and the shear rate at -20 C, 0 C,
and 20
C. As shown in FIG. 6, the fluid exhibits a higher apparent viscosity under a
low
shear rate, and as the shear rate increases, the viscosity decreases
significantly. Thus,
the fluid shows an obvious shear-thinning behavior, which is consistent with
the
rheological behavior of a non-Newtonian deicing/anti-icing fluid. Moreover,
the
zero-shear viscosity of the deicing/anti-icing fluid significantly increases
as the
temperature decreases, and the viscosity is greater at a low temperature,
making the
deicing/anti-icing fluid suitable for low-temperature environments.
Example 11
In this example, the components of the deicing/anti-icing fluid, the content
of each
component, and the preparation method are the same as those in Example 2.
The relationship between the apparent viscosity of the deicing/anti-icing
fluid and
the shear rate is determined at -20 C, 0 C, and 20 C. As shown in FIG. 7, at
the
investigated temperatures, the fluid exhibits a stable shear platform and has
a higher
apparent viscosity under a low shear rate, and as the shear rate increases,
the viscosity
decreases significantly, that is, the fluid shows an obvious shear-thinning
behavior,
which is consistent with the theological behavior of a non-Newtonian
deicing/anti-icing
fluid.
Example 12
In this example, the components of the deicing/anti-icing fluid, the content
of each
component, and the preparation method are the same as those in Example 3.
The relationship between the apparent viscosity of the deicing/anti-icing
fluid and
the shear rate is determined at -20 C, 0 C, and 20 C. As shown in FIG. 8, the
fluid
exhibits a higher apparent viscosity under a low shear rate, and as the shear
rate
increases, the apparent viscosity decreases significantly. Thus, the fluid
shows an
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obvious shear-thinning behavior, which is consistent with the theological
behavior of a
non-Newtonian deicing/anti-icing fluid.
Example 13
In this example, the components of the deicing/anti-icing fluid, the content
of each
component, and the preparation method are the same as those in Example 6.
The bottom halves of an aluminum substrate, a glass substrate and a plastic
substrate are immersed in the deicing/anti-icing fluid separately, and the
deicing/anti-
icing fluid easily adhere to the surfaces of these substrates. The substrates
are then
placed in an environment with a temperature of -20 C and a relative humidity
of 40%.
5h later, the surfaces of the substrates adhered with no deicing/anti-icing
fluid are
almost completely frozen, while the surfaces adhered with the deicing/anti-
icing fluid
are nearly unchanged (FIG. 9). It can be seen from above that the deicing/anti-
icing
fluid has excellent anti-icing performance.
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