Abstract

Baker, C. S. L., and Fulton, W. S. (Malaysian Rubber Producers' Research Association). This article provides an overview of natural rubber, derived from the tree Hevea brasiliensis. It summarizes the history of natural rubber with the seedlings planted in Malaysia in 1877, through to the production figures of the present day. It discusses latex collection and its coagulation to give the various types of dry natural rubber grades. The latter are individually described, up to the modern technically specified grades. Raw rubber properties, such as crystallization, storage hardening, cure behavior, and plasticity retention index are covered, followed by treatment of the chemistry and technology of natural rubber. The technical advantages of natural rubber, blends with synthetic rubber, the various vulcanization systems available with the resulting key properties, and antidegradant agents are each outlined. For completeness of coverage of natural rubber, modified forms are discussed, with their attendant change in properties, including those of thermoplastic natural rubber.

Blends and application areas are followed by a final section on natural rubber latex. Latex preparation, concentration, and properties are described, together with an indication of consumption patterns and principal product groups. The concern over protein allergy in latex gloves and condoms is addressed and an explanation on the apparent explosion of interest in this phenomena is given.