1. Definition of rubber
The word “rubber” comes from the Indian language cau uchu, which means “weeping tree”.
The definition in ASTM D1566 is as follows: rubber is a material that can quickly and effectively recover its deformation under large deformation and can be modified. The modified rubber cannot be (but can be) dissolved in boiling solvents such as benzene, methyl ethyl ketone, ethanol toluene mixture, etc. The modified rubber was stretched to twice its original length at room temperature and kept for one minute. After removing the external force, it could recover to less than 1.5 times its original length in one minute. The modification referred to in the definition essentially refers to vulcanization.
The molecular chain of rubber can be cross-linked. When the cross-linked rubber is deformed under external force, it has the ability to recover quickly, and has good physical and mechanical properties and chemical stability. Slightly crosslinked rubber is a typical high elastic material.
Rubber is a polymer material, which has many common characteristics of this kind of materials, such as low density, low permeability to fluids, insulation, viscoelasticity and environmental aging. In addition, the rubber is soft and low in hardness.
2. Main classification of rubber
Rubber is divided into natural rubber and synthetic rubber according to raw materials. It can be divided into block raw rubber, latex, liquid rubber and powder rubber according to the shape.
Latex is a colloidal water dispersion of rubber; Liquid rubber is an oligomer of rubber, which is generally a viscous liquid before vulcanization;
Powder rubber is used to process the latex into powder for batching and processing.
The thermoplastic rubber developed in the 1960s does not need chemical vulcanization, but uses the processing essentials of thermoplastic plastics to form. Rubber can be divided into general type and special type according to use.
3. Use of rubber
Rubber is the basic raw material of the rubber industry, which is widely used to manufacture tires, rubber hoses, tapes, rubber stopper, cables and other rubber products.
4. Application of rubber vulcanized products
Rubber vulcanized products are developed with the automobile industry. The rapid development of automobile industry and petrochemical industry in the 1960s has greatly improved the production level of rubber industry; In the 1970s, in order to meet the needs of high speed, safety, energy conservation, pollution elimination and pollution prevention of automobiles, new types of tires were promoted. Raw rubber consumption accounts for a considerable proportion in transportation.
For example; A Jiefang 4-ton truck needs more than 200 kg of rubber products, a hard seat carriage needs to be equipped with more than 300 kg of rubber products, a 10000 ton ship needs nearly 10 tons of rubber products, and a jet airliner needs nearly 600 kg of rubber. In sea, land and air transportation, no one can do without rubber vulcanized products.
Post time: Jan-03-2023