Rubber is a highly elastic polymer material with reversible deformation. It is elastic at room temperature, under a very small external force can produce a large deformation, remove the external force can restore the original state. This is because the molecular chain of the rubber can be crosslinked. When the rubber after the cross-linking is deformed by external forces, it has the ability of rapid recovery, and has good physical and mechanical properties and chemical stability.

Rubber belongs to completely stereotyped polymer, its glass transition temperature is low, molecular weight is often very large, more than hundreds of thousands. Therefore, the performance of rubber material is very good, which is also one of the main reasons why people rely on it.

Rubber can be divided into natural rubber and synthetic rubber according to the raw materials. Natural rubber material is made of latex, which contains a part of the non-rubber ingredients left in the solid natural rubber. Synthetic rubber is a synthetic high elastic polymer, is one of the three major synthetic materials.

Rubber material can be divided into bulk rubber, latex, liquid rubber and powder rubber. Latex for rubber colloidal moisture dispersion, liquid rubber for rubber oligomer, not vulcanization is generally thick liquid, powder rubber is latex processing into powder, to facilitate ingredients and processing. The thermoplastic rubber, developed in the 1960s, forms without chemical sulfation, but uses thermoplastic processing methods.

Rubber can also be divided into general type and special type of two types. The general performance of general type rubber is good, and it is widely used. Special rubber refers to the rubber with some special properties, like nitrile rubber has oil resistance characteristics, and neoprene rubber has anti-aging characteristics.