In material-sensitive recycling of crushed reclaimed rubber materials, which is achieved by admixing the recycled rubber with new rubber matrices, a drop is noted in the mechanical value level of elastomers. This drop is due to deficient grafting of the recycled rubber with the fresh rubber matrix. To improve grafting quality, the particle surfaces are modified chemically in different ways following a comprehensive morphological and chemical characterization of select types of rubber powder. Grafting with maleic anhydride and grafting of reactive silane-based coupling agents following epoxidation or hydroxylation have shown themselves to be the most promising methods. The criterion applied to evaluate the suitability and effects of the surface modification is the level of or the observable changes in the material's mechanical properties, such as, for example, fracture stress and dynamic modulus.