Surface properties of fillers and interactions with elastomers

In recent years, an increase in the use of composite materials consisting of a polymeric matrix and a filler, such as carbon black or silica, has been observed. It is associated with the outstanding mechanical properties exhibited by such materials, which are dependent on the nature of the polymer-filler interface. In this respect, the physical or chemical interactions the solid surface can exchange with the matrix play an important role.After a short review of the parameters used for the characterization of fillers, and of some of the methods allowing an estimation of their reinforcing ability, the nature of the interactions able to take place between the elastomer and the filler will be examined. For this purpose, two examples will be provided. In the first, the kind of interaction the surface active sites of a filler can exchange with an elastomer will be considered, in the second, the consequences of a selective deactivation of the filler surface on its reinforcing ability will be reported.