Determination of chlorine content in chlorinated, vulcanized natural rubber by XANES

The degree of chlorination in chlorinated, vulcanized natural rubber was determined by X-ray absorption near-edge spectroscopy (XANES). The vulcanized natural rubber samples were prepared in film with thickness of 180 μm, approximately. They were treated with chlorination solution with different immersion times ranging from 0.5 to 30 min. Experimental results implied that incorporated chlorine atoms were covalently bonded to carbon atoms in the rubber molecules. The chlorine content increased with the chlorination time up to 10 min before the absorption was saturated.