rubber

The word rubber comes from the Indian word cau-uchu, which means "tearful tree." Natural rubber is made from the latex that flows out during rubber tapping of the trefoil rubber tree, which is then solidified and dried. In 1770, British chemist J. Priestley discovered that rubber could be used to erase pencil writing. At that time, the material used for this purpose was called rubber, and the term is still used today. The molecular chain of rubber can be crosslinked. When the crosslinked rubber is deformed by external force, it has the ability to recover quickly and has good physical and mechanical properties and chemical stability. Rubber is the basic raw material of the rubber industry and is widely used in the manufacture of tires, hoses, tapes, cables and various other rubber products. Trifoliar rubber trees provide the most commercial rubber. It secretes large amounts of tree sap containing rubber emulsion when it is injured (such as when the bark of the stem is cut open).

In addition, fig trees and some Euphorbiaceae plants can also provide rubber. Germany tried to obtain rubber from these plants during the World War when its rubber supply was cut off, but later switched to producing artificial rubber.

The original rubber trees grew in South America, but after artificial transplantation, a large number of rubber trees were also planted in Southeast Asia. In fact, Asia has become the most important source of rubber.