Sulfur vulcanization been uncertainly as to whether it proceeds in a radical or ionic manner. The reactive sites, often referred to as 'cure sites', are unsaturated groups such as alkenes and allyls. During vulcanization, sulfur bridges are formed between these sites, crosslinking the polymer. These bridges may consist one or several sulfur atoms. Both the extent of crosslinking and the number of sulfur atoms in the crosslinks strongly influences the physical properties of the rubber produced: Sulfur, by itself, is a slow vulcanizing agent and does not vulcanize synthetic polyolefins. Even with natural rubber, large amounts of sulfur as well as high
Frasch process this method, the United States produced 3.89 million tons of sulfur in 1989, and Mexico produced 1.02 million tons of sulfur in 1991. The Frasch process can be used for deposits 50–800 meters deep. 3-38 cubic meters of superheated water are required to produce every tonne of sulfur, and the associated energy cost is significant. A working demonstration model of the Frasch process suitable for the classroom has been described. Frasch process The Frasch process is a method to extract sulphur from underground deposits. It is the only industrial method of recovering sulphur from elemental deposits. Most of the world's