bullet What are the two types of rubber?
bullet Answer : The two types of rubber in common use today are natural and synthetic. Natural rubber comes from the rubber tree (Hevea brasiliensis). When a tree matures at the age of six or seven years, the latex is collected from a diagonal incision in the tree trunk. The tapping process does not affect the health of the tree and the tree wound later heals itself. Synthetic rubber is made by man from petrochemical feedstocks. Crude oil is the principal raw material.
bullet What discovery marked the beginning of modern rubber technology?
bullet Answer : Prior to 1839, the properties of rubber were dictated by the surrounding temperature. During the hot summer, rubber was sticky and malleable, while it became hard and brittle in the colder months. This was finally remedied by the discovery of the process of vulcanization. A mixture of rubber, white lead and sulphur was dropped accidentally upon a hot stove. When it was removed, the material was no longer affected by temperature. Despite stretching, it always returned to its original shape. This process of vulcanization made it possible to use rubber in raincoats, overshoes, and eventually many other products, including tires.
bullet What was the first practical use of rubber?
bullet Answer : In England, Joseph Priestley, best known for his discovery of oxygen, noted that pencil marks could be “rubbed out” by the substance. From this early use, rubber derived its name.
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