Polymer such as rubber, suberin, melanin and lignin. Naturally occurring polymers such as cotton, starch and rubber were familiar materials for years before synthetic polymers such as polyethene and perspex appeared on the market. Many commercially important polymers are synthesized by chemical modification of naturally occurring polymers. Prominent examples include the reaction of nitric acid and cellulose to form nitrocellulose and the formation of vulcanized rubber by heating natural rubber in the presence of sulfur. Ways in which polymers can be modified include oxidation, cross-linking and endcapping. Especially in the production of polymers the gas separation by membranes has acquired increasing
The Sulphur Institute The Sulphur Institute The Sulphur Institute, or TSI, is an international non-profit organization which acts as a global advocate for sulfur and sulfur producers. The Sulphur institute was founded in 1960, initially working with companies involved in the mining of sulfur using the Frasch process. With the increase of the Claus process for extracting sulfur from natural gas and oil, TSI's members now include multinational energy companies. The Sulphur Institute connects these sulfur producers with sulfur's largest consumer markets (fertilzers and construction materials), transporters, traders, and service providers. Today, The Sulphur Institute's member companies include a host of companies from