【正文】 butadiene rubbers, ethylenepropylene rubbers, butyl rubbers, acrylic rubbers, and silicone rubber. More than half of the world’s synthetic rubber is made from the monomers styrene and butadiene. They are abundant in petroleum, which is one reason styrenebutadiene rubber(SBR) has bee so popular. Three quarters of all the SBR made gose into tires, the world’s major rubber product, waterproofed materials, and adhesive. Ethylenepropylene rubbers introduced mercially in 1962 emerged from new research into polymer chemistry. These rubbers are now among the fastestgrowing elastomers. They are used in rubber membranes for roofing, agriculture, and water distribution. Modifications of these rubbers are used in 南華大學(xué)九九級(jí)化學(xué)工程與工藝專(zhuān)業(yè)畢業(yè)論文 第 20 頁(yè) 共 27 頁(yè) radiator and heater hoses, brake ponents, pond and ditch liners, agriculture silos, tank linings, wire and cable, gaskets, and faucet washers. Butyl rubber were developed into mercial products in the 1940s by Exxon Research and Engineering Company. They are used in inner tubes and other products that require a good barrier against gases. The thermal stability of these rubbers makes them suitable for use in automotive radiator hoses. Their ozone resistance makes them appropriate for electrical insulation and for weather resistance. . Their ability to absorb shock is earning them wide application in automotive suspension bumpers. These rubbers also have a few disadvantages: they are inpatible with many natural and synthetic rubbers, they tend to pick up foreign matter and impurities, and they lose elasticity at low temperatures. Acrylic elastomers are used in applications such as spark plug boots, ignition wire jacketing, and hose where oil resistance is crucial. They are not suited for normal tire use, however, because they have little resistance to abrasion at low temperatures. Silicone rubbers perform exceptionally well in Oing and sealing applications. Many types of wire and cable are insulated with these rubbers, which will burn to an ash yet still function as an insulator. Their resistance to moisture makes them good for outdoor applications. Because they are odorless, tasteless, and nontoxic, they are used for gas masks, food and medicalgrade tubing, and some surgical implants. Their use is limited by the high cost of manufacturing these rubbers. Researchers in the synthetic rubber industry continue to seek new ways to make specific processes more efficient, less costly, and less pollutive. They are developing new additives, processes, rubber pounds, and technological applications. By applying rubber cushioning to railway wheels and tracks, for example, city transportation systems are being quieter and smoother. Impactresistant bumpers, shockabsorbing interiors, and crashresistant fuel tanks on cars and trucks help prevent highway deaths and injuries. Rubber 南華大學(xué)九九級(jí)化學(xué)工程與工藝專(zhuān)業(yè)畢業(yè)論文 第 21 頁(yè) 共 27 頁(yè) linings in reservoirs and waste ditches reduce ground and water pollution. Latex is even being used to help stabilize desert soils to make them suitable for agricultural uses. In addition, researchers are studying the fundamental relationships between chemical structures and the features of rubbers of rubber’s macroscopic materials. Such knowledge will enable researchers to design and create specific rubber pounds rather than rely on the timeconsuming methods of trial and error. The handing and recycling of spent tires are a significant and worldwide problem. Billions of discarded tires are currently stockpiled around the world and hundreds of millions are added every year. Those tire stockpiles percent both and environmental hazards. Provided that efficient methods for recycling rubber can be developed, the spent tires could constitute a great asset as a source of raw material .The current usage of spent rubber tires is mainly confined to the production of tirederived fuel for power plants and cement kilns. From an economic and environmental perspective the reuse of rubber material should be preferable to deposition or incineration. A small part of the tire stock is ground and mixed with new rubber. Only a few percent of ground rubber material can be incorporated in the new rubber before critical properties such as modulus and tearstrength are seriously affected. The resulting material has somewhat impaired mechanical properties and this limits potential application areas. The impaired properties are mainly due to the scarcity and weakness of bonds between the crumbs and the new rubber matrix. One possible way to overe this problem is to break the sulfur bridges in the surface of the vulcanized rubber, thereby making the hydrocarbon chains more flexible and increasing the number of reactive sites. The surface of the rubber crumbs will then be transformed from an elastic to a viscous state. It has been shown that it is possible to use sulfuroxidizing microanisms for desulfurization of rubber material. These microanisms oxidize sulfur to sulfate and may break the sulfur bridges in the rubber material. Today, all the 南華大學(xué)九九級(jí)化學(xué)工程與工藝專(zhuān)業(yè)畢業(yè)論文 第 22 頁(yè) 共 27 頁(yè) countries put their efforts on the research with lots of money. Under the leadership of the Central Committee of the Party, China’s rubber industry is developing at a high speed, the rubber industry workers and technicians have made many innov