How to Apply Carbomers?

Carbomers are substances used to control the viscosity of a liquid or to help dissolve and suspend insoluble substances within a liquid.

The most desired properties for Carbomers are;

• Providing high viscosity upon use
• Ensuring high dispersion properties within its application area, meaning it must disperse well in the solvent
• Another key factor is its time-saving properties
• The clarity of the resulting solution
• Ensuring a smooth flow after production

How Is It Used?

When manufacturing a product in the aqueous phase, the mixing speed in the vessel should be moderate. During this process, Carbomer should be slowly sprinkled onto the surface of the water.

To achieve good swelling viscosity within the phase, Carbomer should be sprinkled slowly at a low mixing speed. This ensures better dispersion and allows the carbomer to absorb the solvent effectively.

In some cases, a neutralization step may be necessary during mixing. This process can be performed with a suitable base. Gas may form during neutralization, which can be difficult to remove from the final product. Therefore, turbulent mixing methods should be avoided.

What Substances Are Used for Neutralization with Carbomer?

1. Inorganic Bases
   • Sodium Hydroxide (NaOH)
   • Potassium Hydroxide (KOH)
   • Ammonium Hydroxide (NH₄OH)
2. Organic Bases
   • Triethanolamine (TEA)
   • AMP
   • AMPD

The process is carried out using chemicals like these.

What is the Required Amount of Chemical for Neutralization?

The main challenge with using Carbomer is its solubility and the difficulty in achieving the desired consistency after dissolution. To overcome this, the Carbomer must be neutralized and allowed to swell.

To neutralize 1 g of Carbomer to pH 7, you will need a base. For example, 0.4 g of Sodium Hydroxide (NaOH) or 1.5 g of Triethanolamine (TEA) can be used.

Neutralization with divalent inorganic bases should be avoided. This is because these bases can cause the polymer to precipitate due to the formation of cross-links.

Some forms of Carbomer do not inhibit microbial growth. Therefore, a suitable preservative chemical should be added. An example is Benzophenone-3.

Why is Neutralizing Carbomer Important?

Carbomer is an acidic substance. If not neutralized, it can lower the pH of the product, potentially causing skin irritation and allergic reactions. Additionally, Carbomer's viscosity is pH-dependent. When neutralized, its viscosity becomes more stable, which helps the product maintain its desired consistency.