Which fatty acid-based antifoam agents would you recommend ?
The important factors to be borne in mind when chosing and formulating an antifoam agent are a high degree of surface activity and mobility on the one hand and limited solubility in the surface coating compound on the other. The first two properties are found in fatty acid derivatives if their molecular weight is not too high - the molecule chain should not have more than six to ten C-C bonds.
Furthermore, such compounds should be capable of dissociation. This is a property exhibited by anionic compounds such as sodium stearate and sodium lauryl sulphate, as well as by certain cationic ones such as stearylammonium chloride and cetyl trimethylammonium bromide. Such compounds usually have good anti foam properties and can be used, provided the problem of partial incompatibility of medium and additive has been satisfactorily solved. Here it is important that the molecular structures are different.