A Novel Method of Quantitative Characterization of Filled Rubber Structures by AFAA

摘要

A new method for quantitative analysis of the structure of filled rubbers by atomic force microscopy (AFM) has been developed. A distinctive feature of this approach is the splitting of the detected surface microrelief, at a first stage, into separate structures, designated as clusters. The height level, where the splitting is done, is controlled by the total number of clusters per 1μm~2 (this value must be maximum), their compactness (its minimum value is attributed to branched structures) and their volume fraction (which is approximately equal to the given filler volume fraction). Further stages of investigations include a statistical characterization of the structure and distribution of the clusters. Furthermore, calculations of the Morishita index (a measure of cluster distribution), area, size, perimeter, degree of orientation and fractal characteristics of the examined structures are presented. The validity of the method has been verified by studying EPDM-rubbers filled with N330 carbon black, Silica Aerosil 200 and Aerosil R974 of filler fractions 20 and 40 phr, and by investigating a stretched natural rubber samples filled with N339 carbon black (50 phr).