TECHNICAL DATA SHEET
TDS-243
Edition: October 15, 2007
Previous Edition: January, 2002
Optimizing Performance of Carbopol®* ETD 2020 and Ultrez 10
Polymers with Partial Neutralization of Polymer Dispersions
Unique Dispersions from New
Generation Carbopol® Polymers
Carbopol® ETD and Ultrez polymers are "easy to
disperse" crosslinked polyacrylic acid polymers
synthesized in a toxicologically preferred cosolvent
system of ethyl acetate and cyclohexane.
Although Carbopol® ETD 2020 and Ultrez 10 have
properties similar to traditional Carbopol®
polymers, they are specifically designed to provide
easily made dispersions that are less susceptible
to lumping as well as easier to pump and handle in
processing due to its low dispersion viscosity
before neutralization.
This unique dispersion
performance is derived from their ability to wet
quickly and hydrate slowly, uncoiling at a relatively
slower rate. Dispersions made with Carbopol®
Ultrez 10 and ETD 2020 may appear to be nonuniform, containing visible aggregate particles
which may settle into a separate phase when not
mixed. This is typical of Carbopol® "easy to
disperse" polymers.
Creating Uniform Dispersions
In order to achieve a homogeneous dispersion
without phase separation, it is recommended to
prepare dispersions with a minimum polymer
concentration of 2% by weight. This is especially
true when preparing a stock dispersion that will not
be completely used. This creates a space-filled
dispersion that doesn't phase separate.
Another alternative is to partially neutralize the
dispersion, achieving enough viscosity and yield
value to gain homogeneity and the suspension of
aggregate particles in a continuous phase.
Figure 1 Dispersion Appearance Comparison of Three Types of Carbopol® Polymers (unneutralized)
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The information contained herein is believed to be
reliable, but no representations, guarantees or
warranties of any kind are made as to its accuracy,
suitability for particular applications or the results to be
obtained therefrom.
The information is based on
laboratory work with small-scale equipment and does
not necessarily indicate end product performance.
Because of the variations in methods, conditions and
equipment used commercially in processing these
materials, no warranties or guarantees are made as to
the suitability of the products for the application
disclosed.
Full-scale testing and end product
performance are the responsibility of the user. Lubrizol
Advanced Materials, Inc. shall not be liable for and the
customer assumes all risk and liability of any use of
handling of any material beyond Lubrizol Advanced
Materials, Inc.’s direct control. THE SELLER MAKES NO
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. Nothing contained herein is
to be considered as permission, recommendation, nor
as an inducement to practice any patented invention
without permission of the patent owner.
For further information, please visit www.pharma.lubrizol.com
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© Copyright 2007 / The Lubrizol Corporation
2
Dispersions of three different Carbopol® polymer
types in Figure 1 illustrate the distinct
appearance of dispersions made with these
polymers:
Figure 2
®
Typical Viscosity Response of Carbopol Ultrez 10 and
ETD 2020 During Partial Neutralization Procedure
Neutralized with NaOH (18%)
• Carbopol® 940 - Homogeneous dispersion
• Carbopol® ETD 2020 - Layered phases
• Carbopol® Ultrez 10 - Softly settled polymer
particles
The varying appearances are unique to each
Formulators and
Carbopol® polymer type.
processors working with the various Carbopol®
polymers need to keep in mind that it is typical
for dispersions with Carbopol® ETD 2020 and
Carbopol® Ultrez 10 to form separate layers.
These dispersions can be made uniform with
gentle mixing.
Optimizing Performance in
Surfactant Systems
Besides uniform dispersion preparation, this
concept is also helpful when formulating
Carbopol® ETD polymers in high-active
surfactant systems such as shampoos, bath
gels, hand soaps and facial and body scrubs. In
these
systems,
high
concentrations
of
surfactants prevent uncoiling of Carbopol®
polymer chains if the polymer neutralization is
carried out after the addition of surfactants. This
results in either low viscosity or yield value of the
end product, graininess, insoluble "jelly particles"
(or "fish eyes") and insoluble precipitates. This is
particularly true when cationics or secondary
surfactants, such as amphoterics or alkyl
polyglycosides, are present at higher levels.
Clarity of the final product can also be adversely
affected in such cases.
Normally, for partial neutralization, approximately 10% of total neutralizing agent necessary
for the whole batch should be sufficient. Partial
neutralization will result in an increase in the pH
of the dispersion (approximately 3.8 - 4.0) and
viscosity due to the partial uncoiling or swelling
of the polymer.
The following graph (Figure 2) represent typical
viscosity increases during this procedure.
Any conventional neutralizing agent can be used
in this method but the use of a weaker
neutralizing agent such as a TEA is
recommended for better control of the pH.
Figure 3
®
Dispersion Viscosities of Various Carbopol Polymers