Morphology and dynamic-mechanical properties of SBR-silica compounds used for tyre treads

In the present contribution we report the results of an accurate morphological investigation carried out by Transmission Electron Microscopy (TEM) and Automated Image Analysis (AIA). The digital image analyses, performed on TEM micrographs and optimised within the research carried out in our group for different elastomer matrices, allowed to identify and measure all the dispersed aggregates of filler. Morphological descriptors such as projected area (A), perimeter (P), area/perimeter ratio (A/P) and roundness (P2/4?A) provided direct and quantitative indications about a better distribution of the TESPT-modified silica into SBR matrix. Moreover, the dynamic-mechanical behaviour of these compounds was studied by the determination of dynamic storage and loss moduli (G' and G", respectively) and loss tangent (tan?) as a function of temperature. These results confirm that for the same cross-linking density, the silica modification with TESPT promotes the formation of smaller aggregates and then a higher degree of filler-elastomer interactions.