Carbomer 940 is white, loose, acidic, hygroscopic and slightly odorous, soluble in water, ethanol and glycerol. The common concentration is 0.1% ～ 3.0%.
Carbomer 940 contains a lot of carboxyl groups in its molecule, so the aqueous solution should be used after neutralization with alkali to reduce the irritation to skin and mucous membrane.
The neutralizer of Carbopol 940 can be sodium hydroxide, potassium hydroxide, potassium bicarbonate, borax, amino acids and polar organic amines such as triethanolamine. Laurylamine and Stearylamine can be used as neutralizers in nonpolar systems. The carbomer hydrogel after neutralization is thicker between pH6 and 11, such as pH < 3 or pH > 12, viscosity decreases, and strong electrolyte can also reduce viscosity. The gel is unstable. It is easy to grow mold and lose its viscosity rapidly when exposed to sunlight. Adding antioxidants can slow down the reaction.
Desheng Carbopol 940 sample
Usage and precautions of Carbopol 940 (acrylic resin)
1. PH value: the best pH value range of Carbopol 940 system is 4-10, higher or lower than this range will lead to the change of system viscosity.
2. The ingredients in the formula that are not easy to be compatible: protein, PVP resin, polyethylene glycol (PEG), polyethoxylated surfactant will interact with non neutralized Carbopol 940, so it is necessary to partially neutralize Carbopol 940 before adding. Desheng is specialized in providing raw materials and technical formula support for Kapo 940 and other cosmetics.
3. Salt and soluble cation: Carbopol 940 is sensitive to salt and cation. When the concentration of soluble ion exceeds 0.1%, the dosage of Carbopol 940 should be controlled. If possible, acidic, neutral or alkaline materials should be used as the matrix of the main drug, deionized water should be used, and salt should be added after neutralization to master the influence of salt on the system. High valence ions (CA, Mg, Fe, AI) will cause serious damage to the system and should be eliminated.
Self transformed pollutants (such as Fe, Cu, etc.) will gradually reduce the viscosity of the system and lead to the instability of the system. In addition, adding EDTA to chelate metal ions can also achieve good results. In addition to the above two aspects, we can also choose the appropriate model of Carbopol 940 (such as Carbopol 9401342ge resin), which is less sensitive to soluble salts.
4, insoluble matter: when there are insoluble components, carbo 940 system is difficult to present clear and transparent gel.
