Natural rubber engineering applications

Handbook of elastomers , A.K. Bhowmick and H.L. Stephens Marcel Dekker (1988) Series Plastics Engineering, Volume 19 ISBN 0824778006. This handbook systematically addresses the manufacturing techniques, properties, processing, and applications of rubbers and rubber-like materials. The Handbook of Elastomers provides authoritative information on natural rubbers, synthetic rubbers, liquid rubbers, powdered rubbers, rubber blends, thermoplastic elastomers, and rubber-based composites— offering solutions to many practical problems encountered with rubber materials. 

Polymers for membrane preparation can be classified into natural and synthetic ones. Polysaccharides and rubbers are important examples of natural membrane materials, but only cellulose derivatives are still used in large scale for technical membranes. By far the majority of current membranes are made from synthetic polymers (which, however, originally had been developed for many other engineering applications). Macromolecular structure is crucial for membrane barrier and other properties main factors include the chemical structure of the chain segments, molar mass (chain length), chain flexibility as well as intra- and intermolecular interactions. 

The largest use of natural rubber is in the manufacture of tires. Over 70 percent of its consumption is in this area. The next largest use is as latex in dipped goods, adhesives, rubber thread, and foam. These uses account for approximately another 10 percent. The remainder is used in a variety of applications such as conveyor belts, hoses, gaskets, footwear, and antivibration devices such as engine mounts. 

The major use of polymers has been as replacements for naturally occurring materials. Synthetic fibers such as nylon and polyester have substantially replaced natural textiles synthetic rubber is vastly superior to natural rubber, and the wide variety of engineering polymers (both thermosets and thermoplastics) have replaced traditional, naturally occurring materials such as metals and cellulosic compounds in many applications. 

Tires are one of the most durable technological products manufactured today. They are a resilient, durable composite of fabric, steel, carbon black, natural rubber, and synthetic polymers. The qualities that make tires or other engineered rubber products a high-value item create a special challenge of disposal. Tires and other rubber products, such as conveyor belts and hydrauUc hoses, are not biodegradable and cannot be recycled like glass, aluminum, or plastic. Four potential applications for such products entering the solid waste stream have been identified ... 

MAJOR APPLICATIONS Although sulfur has many industrial apphcations in the area of organic and inorganic synthesis, in the field of pwlymer science and engineering it is probably best known for it use in the vulcanization of natural rubber and related unsaturated polymer chains (see Coran and pertinent references cited therein). 

The temperature range in which each of these three engineering potymers is used is indicated in Figure 4.21. Natural rubber has wide application as an elastomer. Its upper use temperature is determined by the onset... 

Natural Rubber-Based Composites and Nanocomposites Table 1.14 General and engineering applications of... 

The changes in tensile properties, as the temperature rises from 23°C to 210/240°C, follow a consistent pattern and decrease uniformly. It is specially observed that these PUs show no sharp melting points accompanied by rapid loss in dimensional stability. This is a characteristic usually shown by the traditional covalent crosslinked rubbers such as NR, CR, etc., and is of importance in engineering applications where it is essential to avoid failures of a catastrophic nature which may occur if a polymer possesses a sharp melting point. 

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