Rubber is indispensable in modern production, military industry and daily life. More than 150 years ago, people could not make it. They only knew how to obtain raw rubber from rubber trees. It was very soft in hot weather, but became oaky in winter. The board is so hard. Coating raw rubber on cloth to make a tape raincoat can only be used in warm seasons.
In 1838, American Goodyear discovered that if raw rubber is heated with a small amount of sulfur, the product obtained is much better than ordinary raw rubber and can remain soft whether in winter or summer. Rather than sticky. Rubber treated in this way is called vulcanized rubber. Nowadays, the rain boots, bicycle tires, rubber gloves and other rubber products we wear are almost all vulcanized. If a considerable amount of sulfur is added, it will become hard rubber.
Sulfur will make rubber "tame". The carbon atoms in the rubber molecules are like a carbon chain, one after another, and these carbon atoms pull two hydrogen atoms. These molecules are connected together like a long line, which is called a linear structure. If sulfur is mixed into the rubber molecules and heated, the sulfur can cleverly build bridges between linear molecular chains, turning the linear molecules into a network structure, doubling the strength of the rubber.
However, processing raw rubber into rubber products requires 12 processes including batching, mastication, mixing, calendering, extrusion, and vulcanization. If it is processed into tires, the two processes of molding and vulcanization are quite different from other rubber product production processes.
In addition, when adding ingredients, in addition to adding sulfur, magnesium oxide, vulcanization accelerators, antioxidants, reinforcing agents, softeners and colorants are also needed. This is like building a building. Bricks, tiles, sand and gravel also need steel bars and cement. After adding many chemicals and heating, the elasticity, strength, and wear resistance of rubber are significantly improved. Rubber products such as rubber shoes, hot water bottles, tapes, raincoats, and tires are made into shiny and durable rubber products. durable.