Vulcanization: Vulcanization is very widely used in rubber technology to improve the properties such as low tensile strength, plastic nature, thickness etc. by adding some chemicals like sulphur, hydrogen sulphide, benzene chloride etc. it is done by heating of raw rubber with sulphur at 100: 140 degree centigrade temperature. The added sulphur combines chemically as the double bonds of different rubber springs. Sulphur can also bring about vulcanization without affecting the double bonds in the polymer molecule, by eliminating H₂S. The rate of vulcanization of rubber is quite slow and also depends upon the types and quality of rubber used. But, by using certain organic compounds called accelerators, vulcanization reaction speed up.