The universal usefulness of stearic acid as surface modifier: applications to the polymer formulations and composite processing

This work aims to review the literature studies based on the application of stearic acid (SA) in a large range of industrial and academic formulations, given the benefits arisen from this additive on the functional and structural properties of the manufactured products. The SA is characterized by a long hydrocarbon non-polar chain endowed with a terminal polar carboxyl group. In primary usefulness consists in a lubricant effect, by positively affecting the materials workability, and in the ability to interact with various surfaces through physical or chemical mechanisms, by creating layer structures. In these conditions, a reduction of the surface energy and an increase of the hydrophobic character have been promoted in the treated surfaces. These aspects have played an interesting role in the compounding phase of a composite system, by promoting a reduction of the mixture viscosity, an increase of filler/matrix compatibility, and an improvement of filler dispersion.