vulcanization

n. method of treating crude rubber with sulphur and exposing it to high temperatures to increase its durability and elasticity

Vulcanization refers to a specific curing process of rubber involving high heat and the addition of sulfur. It is a chemical process in which polymer molecules are linked to other polymer molecules by atomic bridges composed of sulfur atoms. The end result is that the springy rubber molecules become cross-linked to a greater or lesser extent. This makes the bulk material harder, much more durable and also more resistant to chemical attack. It also makes the surface of the material smoother and prevents it from sticking to metal or plastic chemical catalysts.
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Noun
1. process of treating rubber or rubberlike materials with sulphur at great heat to improve elasticity and strength or to harden them
(synonym) vulcanisation
(hypernym) processing
(derivation) vulcanize, vulcanise

(n.)
The act or process of imparting to caoutchouc, gutta-percha, or the like, greater elasticity, durability, or hardness by heating with sulphur under pressure.
  

A process of combining rubber with sulfur or other substances that causes the polymer chains to crosslink, making them stronger and more elastic.