Analytical Method for Rubber Materials Using Sulfur K-edge NEXAFS and Its Application

Here, we develop a technique for curve-fitting of the sulfur K-edge near-edge X-ray absorption fine structure (NEXAFS) to analyze crosslinked vulcanized rubber based on chemical state sulfur. The proposed analytical method provides chain length (Sx), crosslink density, and oxide content simultaneously, it is highly sensitive analysis depth direction. Furthermore, verify aging mechanism using this method. It found that chains, shortened oxidized by heat at 120°C, can cause scission S—C bond, thereby decreasing density. Long chains are more susceptible oxidation, which rapidly decreases (Sx) and, in turn, density compared with short chains. By comparing heat-aging dependence between bond S100, styrene-butadiene polymer surface form C—C crosslink. We present establish NEXAFS as useful materials.