Causes of Abnormal Viscosity in Carbomer 940 and Scientific Solutions

Carbomer 940, as a commonly used high-molecular-weight polymer, is widely applied in daily chemical and pharmaceutical industries for thickening, suspension, and system stabilization. Its viscosity properties directly affect product performance and quality stability. In practical applications, issues such as viscosity falling below expected values or gradual viscosity decline often arise. While these two problems appear similar, their causes and resolution logic differ significantly, necessitating targeted measures tailored to specific scenarios.

Treatment strategy for Carbopol 940 viscosity lower than expected

When the viscosity of the Carbopol 940 system measured during the preparation process does not meet the design standards, it is necessary to investigate and adjust it from three dimensions: stirring method, component compatibility, and system compatibility, in order to avoid blindly increasing the dosage and causing cost waste or performance imbalance.

Carbomer

Firstly, it is necessary to optimize the mixing operation to avoid excessive shearing. The thickening principle of Carbopol 940 relies on the sufficient stretching and entanglement of polymer chains. If high shear stirring equipment (such as high-speed dispersers) is used or the stirring time is too long, it will damage the molecular chain structure, causing it to be unable to form a stable three-dimensional network structure, thereby reducing viscosity. In practical operation, it is recommended to use medium and low-speed stirring equipment, control the stirring rate at 300-500 revolutions per minute, and stop stirring after Carbopol 940 is completely dispersed and dissolved to ensure that the molecular chains remain in a complete extended state.

The coping method for the decrease in viscosity of Carbopol 940 over time

The decrease in viscosity during storage or use is often related to component degradation and environmental impact, and requires protection from three aspects: raw materials, storage, and additives. ​

1. Strictly avoid the addition of incompatible ingredients. Some components can accelerate the degradation of the molecular chain of Carbopol 940, such as strong oxidants (such as peroxides), strong acids and bases (pH values exceeding the range of 2-11), or certain enzyme substances, which can damage the carboxyl structure of Carbopol 940 and gradually lose its thickening properties. When designing the formula, it is necessary to clarify the chemical properties of the raw materials to avoid including the above-mentioned taboo ingredients in the system; If it is necessary to add due to functional requirements, stability tests should be conducted to verify its effect on viscosity. If necessary, the order of addition should be adjusted or microcapsule encapsulation technology should be used to reduce direct contact.

2. Optimize storage conditions. Ultraviolet radiation, high temperature, and heavy metal ions can cause a decrease in viscosity: ultraviolet radiation induces photooxidation, high temperature accelerates chain breakage, and heavy metal ions catalyze oxidation. Storage should be cool and dark, with a temperature of 5-30 ℃. HDPE plastic or glass packaging should be selected to prevent heavy metal leaching; Avoid contact with metal utensils during use. ​

3. Reasonably add auxiliary stabilizers. Chelating agents (such as EDTA-2Na, 0.01% -0.1%) can bind heavy metal ions, while UV absorbers (such as benzophenones, not exceeding 0.5%) can absorb UV radiation and reduce degradation. The dosage should be controlled to avoid affecting the transparency or irritability of the product. ​

Shipping packaging

In summary, to solve the abnormal viscosity of Carbopol 940, it is necessary to first identify the type of problem and then make adjustments in terms of process, formula, storage, and other aspects. Scientific control can ensure its viscosity performance, improve product stability and user experience.

The carbomer sold by Hubei Xindesheng Material Technology Co., Ltd. is a very fluffy white powder substance that becomes a viscous transparent substance after preparation. Adding it to various skincare products not only does not affect its effectiveness or appearance, but also has certain benefits. If you have any relevant procurement needs, please click on our official website to learn more details or contact us