Rubber (Rubber): highly elastic polymeric material with reversible deformation. It is elastic at room temperature and can produce great deformation under very little external force. It can be restored to original state after removing external force. Rubber is completely amorphous polymer, its glass transition temperature (T, g) is low, the molecular weight is often large, more than hundreds of thousands.
The word "rubber" comes from the Indian language "cau-uchu", meaning "weeping tree"". Natural rubber is flowing out from the Hevea latex when tapping after solidification and drying process. In 1770, British chemist J. Priestley discovered that rubber could be used to erase pencil writing. The material used at that time was called rubber, which has been used so far. The molecular chain of rubber can be crosslinked, and the crosslinked rubber can recover quickly when it is deformed by external force, and has good physical and mechanical properties and chemical stability. Rubber is the basic raw material of rubber industry. It is widely used in making tyres, rubber hoses, tapes, cables and other kinds of rubber products.