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
Polymer Corporation Polymer Corporation Polymer Corporation was a Canadian federal crown corporation established in 1942 to produce artificial rubber to substitute for overseas supply cut off by World War II. After the Japanese captured the Dutch East Indies in 1942, most of the world's supply of natural rubber was out of Allied hands. Due to the importance of rubber products for both modern life and modern warfare, the loss of such an important resource at this phase in the war was a crisis. A factory was established in Sarnia, Ontario, using German patents from an American licensee. Polymer produced approximately 3,300 tons