The term elastomer is sometimes used to designate synthetic rubber only and is sometimes extended to include caoutchouc as well. All rubberlike materials are polymers , which are high molecular weight compounds consisting of long chains of one or more types of molecules, such as monomers. Natural rubber is a polyterpene, i.e., it consists of isoprene molecules linked into loosely twisted chains. In gutta-percha , which is another natural polyterpene, the isoprene molecules are bonded in a trans configuration leading to a crystalline solid at room temperature. Unvulcanized rubber is soluble in a number of hydrocarbons, including benzene, toluene, gasoline, and lubricating oils.
Rubber is water repellent and resistant to alkalies and weak acids.
Rubber s elasticity, toughness, impermeability, adhesiveness, and electrical resistance make it useful as an adhesive, a coating composition, a fiber, a molding compound, and an electrical insulator. The advantages of natural rubber are less buildup of heat from flexing and greater resistance to tearing when hot. Complete story. . All copyrights belong to the original works and authors.