What is Carbomer?

Carbomers are compounds produced by polymerizing acrylic acid in the presence of a solvent and other chemicals. Carbomer is the commercial name for the product. It can be found on the market under various names and codes. Additionally, another company offers commercial products under the name Carbopol.

Physical and Chemical Properties

Physically, it is a white powder. The most important chemical property of carbomers is their thickening ability. They work by increasing the viscosity and providing consistency to the mixtures or compounds they are added to.

Types of Carbomer

Carbomer 940
Carbomer 980
Carbomer 930
Carbomer 940
Carbomer 980
Carbomer 938
Carbopol
Carbopol
Carbomer 841

Working Principle

Carbomers act as thickeners and stabilizers due to their high solubility in water and polar solvents. The hydrophilic properties of these polymer substances have facilitated their place in the commercial market. When added to water and polar solvents, they rapidly absorb water and dissolve. At the same time, improper dissolution procedures can lead to the formation of aggregates.

The hardening process is explained as follows: The polymer particles are in the form of a powder aggregate. The outer surface of this powder aggregate prevents the inner part of the particle from getting wet. This causes the outer surface to harden, blocking water from reaching the interior.

The method for adding carbomers to water depends on the desired amount and concentration of the dispersion. The optimal mixing speed is 800-1200 rpm. The motorized mixers used for adding the polymers should be capable of agitating mixing.

High-shear mixers should be avoided. Using mixers with this type of action causes a permanent loss of viscosity in carbomers. This issue is so critical that losses can reach up to 50%. Since these substances are used for their viscosity-increasing and thickening properties, this would present a significant cost disadvantage.

How to Add Carbomer to a Mixer

Before starting the mixing process, the impeller inside the mixer is lowered to the very bottom point. This helps create agitation and a vortex during mixing. After the solvent is added, mixing begins at 1200 rpm. Once a sufficient vortex has formed, the carbomers are added through a sieve into this vortex. The purpose is to ensure that every Carbomer particle is wetted within the solvent vortex.

Using a metallic sieve will generate minimal static charge. The mixing speed should be reduced during the addition to prevent excessive air entrapment.

An emulsifier is added before the neutralization process.

Neutralizing Agents

Alkali metal solutions (NaOH and KOH) neutralize Carbomer solutions containing less than 20% Ethyl Alcohol.
Triethanolamine (TEA) neutralizes Carbomer solutions containing up to 50% Ethyl Alcohol.
2-Hydroxypropylethylenediamine can neutralize solutions containing up to 70% Ethyl Alcohol.

Additionally, some types of carbomers have different polymerization agents.

Applications

It acts as an emulsifier, preventing the separation of oil and liquid components within a solution.
In cosmetic products, it helps to control texture, consistency, and flow.
Carbomer is used to provide a gel-like consistency in the manufacturing of antibacterial gels.
It is used in the cosmetics industry to provide consistency in the manufacturing of products such as makeup, hair, nail, and skin care items.
In some formulations, they help to disperse and suspend insoluble solid particles in water.
It is used as a rheology modifier in the production of tire repair creams.
It is used together with methyl alcohol in the production of chafing fuels used in applications like barbecues.