Skip to blog entries Skip to archive page Skip to right sidebar
WORKING WITH CARBOMER (PART I)
SWETTIS BEAUTY BLOG
Saturday, 28. December 2013
Working with Carbomer (part I)
Carbomer powder
Preparing stable gels and viscosity control are among the most significant challenges of each
formulator. Viscosity control is most often performed with synthetic (e.g. polyacrylates) or
natural polymers (e.g. Xanthan gum), each one having its significant characteristics, advantages
and limitations.
One of the most versatile polymers in industry, cosmetics and pharmaceuticals and even in oral
care products is a group of polyacrylates under the INCI name of Carbomer.
Carbomer family has several members with individual characteristics. All of them based on
acrylate
Acrylate as the building block of carbomer
Each one having its specific characteristics concerning the viscosity, electrolyte tolerance,
compatibility with other ingredients, etc. One of the most widely used Carbomers however is
Carbomer 940 .
Carbomer is the main part of almost every cosmetics and pharmaceutical product which is
offered as a gel, from cosmetic glitter gels to cuticle removers to gel toothpastes. It is a viscosity
modifier, stabilizer, dispersant and emulsifier. Do you posses one of those small bottles of hand
sanitizer gels in your purse to disinfect your hands as you're out of home? Have a look at the
bottle. It contains about 0,5% Carbomer.
glitter gel with carbomer
I've prepared hundreds of products based on Carbommer (have a look at my previous tutorial:
Ice gel for heavy legs as an example). For the upcoming tutorials however, I want you to have a
clear understanding of the chemistry and characteristics of the poylmer before you start working
with it.
Disclaimer: Polyacrylates are synthetic polymers, if you generally avoid synthetic ingredients in
your formulations, you do not need to read the whole story.
Carbomer 940 is a fluffy hygroscopic, light white powder which is dispersible, but not soluble in
water and in alcohol.
As the polymer is dispersed in water or in alcohol, it has a pH of about 3 (very acidic) and it
builds a turbid medium viscosity liquid (the molecules swell in water but not dissolve). This liquid
is called mucillage.
a mucillage of carbomer
Only after the acidic mucillage is neutralized with a base (such as sodium hydroxide solution,
the same thing we apply in our lye preparation only at a much lower concentration, or
triethanilamine) the polymer chains start to organize themselves
polyacrylate chain
in an ordered manner building a clear, high viscosity gel
clear glitter gels with carbomer
Since the gel has a high yield stress, you can disperse and suspend small particles (such as
glitters in the above photo) or even air bubbles in it. Those gels are all prepared from a 0,5%
mucillage.
The viscosity (and the structure) depends on the pH. The highest pH (and transparency) is
between 6-7. Over neutralization above a pH of 7 would cause a reduction in the viscosity and
transparency of the product. This is something you should consider when choosing your
preservative system. Those systems which are effective at a pH around 5 would not be suitable
for Carbomer-based products. I'm applying Euxyl™ PE9010 which is based on Phenoxyethanol
since years and I'm quite satisfied with it. If you decide to apply another preservative, make sure
it is compatible with carbomer and your other ingredients.
In the below diagram you can see the viscosity of a 0,5% mucillage as a function of the pH
viscosity of Carbomed as a function of pH
The viscosity is however very susceptible to electrolytes. There are other grades of carbomer
with higher electrolyte tolerance but for Carbomer 940, the viscosity falls as soon as you have
small amounts of any electrolyte in the medium.
In the following diagram you see the reduced viscosity as a function of added table salt (NaCl)
to a 0,5% neutralized gel.
viscosity of carbomer gel vs electrolyte
Working with carbomer is very exciting and fascinating. Preparing the mucillage is the most
tricky part (but from my point of view it is easier than preparing Xanthan gum solutions).
Follow me to the next part for a tutorial on how to prepare Carbomer gels.
BeHappy and have fun
in SkinChakra Cosmetic Lab at 15:55 | No comments | 3 Trackbacks
Calendar
Back February '23
Mo Tu We Th Fr Sa Su
Sunday, 26. February 2023
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28
Kategorien
Business talk
Cosmetic Chemistry
Giveaways
Oil of the month
Tutorials
AromaCare Lab
SkinChakra Cosmetic Lab
Bath & Body products
Creams & lotions
Facial Care
Hair care
Soap projects
Quicksearch
Archives
February 2023
January 2023
December 2022
Recent...
Older...
Powered By
Serendipity PHP Weblog
Bookmarks
Follow us on Facebook
Serendipity
Datenschutz
Based on the s9y Bulletproof template frameworkPowered by s9y – Template by Bulletproof
development team.
Skip to blog entries Skip to archive page Skip to right sidebar
WORKING WITH CARBOMER (PART II)
SWETTIS BEAUTY BLOG
Monday, 6. January 2014
Working with Carbomer (Part II)
Carbomed gel-Viscosity measurement
Click here for part I.
The fascinating fact about carbomer is its becoming gel only after neutralization. It means you
can prepare a mucillage in advance and keep it (if preserved) even for weeks and then use it
according to your requirements, adding all your ingredients and additives and neutralizing at the
very last step.
I always have a 0,5% mucillage in stock which I prepare and apply weekly. Once you've learned
how to prepare the mucillage and after you've prepared your first couple of batches it becomes
as easy as dissolving sugar in water.
So let's start with the essentials of preparing a mucillage:
1- Prepare your first batches in as small quantities as possible (50 or 100 ml would be the best).
It's a pitty if something goes wrong and you have to discard a 500 ml batch.
2- The most important part of dispersing carbomer is to avoid clumps (similar to Xanthan gum or
cmc or tylose). Once clumps are build, it is almost impossible to rescue the mucillage unless
you have a very effective turbo mixer or ultrasound mixer.
a 0,5% Mucillage is a reasonable starting concentration. Even if you add additives later on
(fragrance oil, color, emollients) the final preparation has a gel like consistency.
Clumps are build as the outer surface becomes wet and swells while the inner part remains dry.
The thinner a film is, the easier it is that the whole volume gets wet and the less the chance of
building clumps.
a) Working with alcohol
The easiest way to prepare a mucillage is to disperse carbomer in alcohol (ethanol or isopropyl
alcohol both work). If your formulation contains alcohol or can tolerate alcohol, disperse the
carbomer in alcohol first.
For an example of dispersing carbomer in alcohol have a look at our tutorial "Happy Feet".
The best way to prepare Carbomer is applying a magnetic stirrer but don't be disappointed if
you don't have any, you can still prepare the dispersion.
Measure your alcohol into a beaker (by weight or by volume).
Sprinkle carbomer over the surface of alcohol. (if you're using a magnetic stirrer sprinkle
carbomer as the magnetic stirrer is off). Add your carbomer in small portions. Wait until the
carbomer over the surface is wetted. You'll observe a change in the appearance. The white
powder becomes translucent as it wets.
Carbomed wetting
After the film is wet and became translucent turn the stirrer on for a short time or stir with hand
for a few seconds. This moves the wet film from the surface to the bulk of the alcohol. Then stop
stirring and add another portion. Continue this process until you've applied the whole carbomer.
Then stir for another couple of minutes and make sure you have no clumps. At this stage and
before adding water you've still a chance of breaking the clumps with a glass rod or spatula.
After you're satisfied with the mixture add the required amount of water under stirring. You'll still
have a non-homogeneous and non transparent medium viscosity mixture.
Carbomer mucillage
You can use this mucillage immediately or preserve and keep it in a closed bottle for later
application.
b) alcohol free preparations
If you don't have any alcohol in your formulation, preparing mucillage is a little bit more tricky.
Keep in mind that the higher the water temperature, the faster and the easier the wetting. And
the larger the surface of the water the easier the dispersion and the wetting.
Add your water to a beaker with a large surface (a 500 ml beaker works well). You don't need
an exact amount of water because water is going to evaporate, but you need the exact weight of
your beaker (and the magnet rod if you're applying one) so that you can compensate the water
loss at the end.
Heat up the water (preferably in a water bath). The water bath should be around 80 degrees
Celsius. Let the water get warm. Sprinkle small amounts of carbomer over the surface of the
water. Sprinkle so much that a very thin film covers the water surface.
Carbomer over water surface
Wait until this portion is completely wet. The powder becomes translucent as it wets.
Caromer getting wet
Now turn the stirrer for a short time or stir with a glass rod until the wet powder is transfered
from the surface to the bulk.
Stop stirring and add another portion to the surface. Repeat the procedure: "Adding powder to
surface, waiting till the powder is wet, stirring" until the whole powder is dispersed in water.
Stop heating and stir with a stirrer or with a glass rod.
Add the lost water and bring your mucillage to 0,5% concentration.
carbomer mucillage
This is the translucent, medium viscosity mucillage. Use it immediately or store it in a well
closed bottle for later use. In the latter case you should apply a suitable preservative. We
recommend Euxyl PE9010 for Carbomed preparations.
c) Neutralisation
It is advisable to add all your other ingredients (preservative, fragrance, colorants, dispersed
particles etc.) before neutralization.
Carbomer mucillage has an acidic pH of around 3,5. Only after neutralization the polymer
chains are organized and a clear, stable, high viscosity gel is formed. (Look at part I for a
diagram of viscosity vs. pH).
Neutralization is performed with an alkaline solution. This could be NaOH (the same thing we
prepare our lye solutions with) or Triethanolamine or any other base. For us soap makers,
neutralization with NaOH is the most comfortable and suitable method.
Although the lye solution is generally much less concentrated (10,0%) compared to the lye
solution for soap making, I still recommend you to reread our advisory post regarding safe
handling of NaOH.
Generally, only a few drops of NaOH (a 10,0% solution) are enough to increase the pH from
around 3,5 to around 6,5-7,0. Add dropwise and stir gently after each drop to check the pH,
viscosity and clarity of the mixture. Even after addition of the first drop a significant change in
viscosity and clarity happens. Unless you prefer to have air bubbles in the gel try to stir very
gently to avoid bringing bubbles. It is very hard to get rid of air bubbles in such a gel with a high
viscosity and yield stress.
neutralized carbomed gel
Check the pH after each addition with a pH indicator paper or an electronic pH-meter attached
to a glass electrode.
If you over neutralize, the viscosity will decrease and the gel becomes slightly translucent. This
is wished for specific products such as cuticle softeners but generally for bath & body products a
max. pH of 7 is wished.
The gel, if preserved correctly would be stable over years. I have gels for over 5 years but the
shelf life of the product depends on your other ingredients as well.
This was a basic to working with carbomer. In coming tutorials we're going to prepare interesting
products with carbomer.
You can purchase all necessary ingredients and tools in SkinChakra® Online shop.
BeHappy and have fun
in SkinChakra Cosmetic Lab at 10:49 | No comments | 2 Trackbacks
Calendar
Back February '23
Mo Tu We Th Fr Sa Su
Sunday, 26. February 2023
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28
Kategorien
Business talk
Cosmetic Chemistry
Giveaways
Oil of the month
Tutorials
AromaCare Lab
SkinChakra Cosmetic Lab
Bath & Body products
Creams & lotions
Facial Care
Hair care
Soap projects
Quicksearch
Archives
February 2023
January 2023
December 2022
Recent...
Older...
Powered By
Serendipity PHP Weblog
Bookmarks
Follow us on Facebook
Serendipity
Datenschutz
Based on the s9y Bulletproof template frameworkPowered by s9y – Template by Bulletproof
development team.
