Carbomer 940 can be said to be a very classic Carbomer material. The appearance is white loose powder. It is very hygroscopic. It is used as a thickener, emulsifier, suspending agent for various daily chemical, skin care, medicinal. In accessories such as gel emulsion products. Most people may not understand its specific ingredients, this article will briefly introduce.
Carbomer 940, like other carbomers, is a copolymer of polyalkyl sucrose or polyalkyl pentaerythritol and acrylic acid cross-linked polymer. Because it is a polymer, its composition actually refers to the monomer before it is polymerized The composition is acrylic or acrylate. In the dry powder state, the carbon chains of individual acrylic molecules are relatively tightly aggregated, but after being easily dissolved in water, the molecules will gradually disperse, forming hydrated molecules with water molecules, so that the tight carbon chains are dispersed, so the viscosity of the entire dispersion system Also began to increase. The greater the degree of carbomer molecule development, the greater the viscosity. Usually, a neutralizing agent such as sodium hydroxide or organic amine is added to make it fully stretched.
Carbomer molecular structure
On the other hand, in the composition of carbomer 940, each acrylic acid has an acidic group, which is weaker than acetic acid and has a pH of 2.5-3.5 when dissolved in water. The higher the carbomer concentration, the higher the carboxyl group concentration. The higher the pH, the lower. Pom is easy to generate salts, and when neutralized with alkali, a large amount of ionized carboxyl groups generate negative charges, which will form a repulsive force with each other and make their molecules stretch more. When neutralized to a pH value of 5-9, the carbomer molecule can swell 1000 times and the diameter increases 10 times, the thickening performance is much higher than other thickeners.
When the Carbomer 940 is used, due to its high performance, the amount of addition is very small, usually only 0.2% -1%. In some cases, it will be slightly higher. Generally, the amount of emulsion added is less, and the amount of addition when made into gel Relatively more. When the carbomer is dissolved with polyhydric alcohol or polyethyl solvent without water, hydrogen bonds generated by the carbomer molecule and the solvent can be generated without adding a neutralizer, resulting in strong thickening and suspending properties.
