Natural rubber (NR)

The material. Natural rubber was known to the natives of Peru many cen­turies ago and is now one of Malaysia’s main exports. It made the fortune of Giles Macintosh who, in 1825, devised the rubber-coated waterproof coat that still bears his name. Latex, the sap of the rubber tree, is cross-linked (vulcanized) by heating with sulfur; the amount of cross-linking determines the properties. It is the most widely used of all elastomers—more than 50% of all produced.

Composition

(CH2—C(CH3)—CH—CH2)n

General properties

Density

Price

Natural rubber is used in medical equipment, fashion items, tubing, and tires.

Typical uses. Gloves, car tires, seals, belts, antivibration mounts, electrical insulation, tubing, rubber lining pipes, and pumps.