Tony O’Lenick looks to Sergio R.S. Costa, of Chemflex Quimica, to explain the difference between carbomer and alkyl carbomer.
Carbomer: The term carbomer refers to a series of polymers of acrylic acid used as thickening agents and emulsion stabilizers to provide suspending proprieties to aqueous formulations. Carbomers are all chemically similar, differing from each other only in their molecular weight, or “n” value, and viscosity. Carbomers have the ability to absorb and retain water, and these polymers can swell to many times their original volume. In addition, these products are not dispersants and have no tolerance to electrolyte, which can limit their use in some applications. Carbomers are used in many applications including hair gels, silicon gels, etc.
Alkyl Carbomer: Alkyl carbomers are a new family of copolymer resins, developed as recently as the 1980s. These products are the result of the copolymerization of acrylic acid and alkyl acrylate. The presence of a hydrophobic alkyl group has several effects upon the product. The alkyl product improves electrolyte tolerance and is much easier to disperse. This class of polymers is used in applications where the standard carbomers cannot provide satisfactory results, including hand sanitizers, lotions, creams and shampoos.
The difference chemical difference between a regular carbomer and alkyl carbomer is the presence of the alkyl group; the main difference between the two is in their formulation. If thickening is required and the standard carbomer works well, it is generally recommended. If, however, the presence of electrolyte is incompatible with the formulation or there is a problem with dispersion in the formulation, alkyl carbomer is recommended.