Branching (polymer chemistry) Branching (polymer chemistry) In polymer chemistry, branching occurs by the replacement of a substituent, e.g., a hydrogen atom, on a monomer subunit, by another covalently bonded chain of that polymer; or, in the case of a graft copolymer, by a chain of another type. Branched polymers have more compact and symmetrical molecular conformations, and exhibit intra-heterogeneous dynamical behavior with respect to the unbranched polymers. In crosslinking rubber by vulcanization, short sulfur branches link polyisoprene chains (or a synthetic variant) into a multiply branched thermosetting elastomer. Rubber can also be so completely vulcanized that it becomes a rigid solid, so hard
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