ABSTRACT
Rubber is to rubber compounds as flour is to bread: although the choice and amount of additives can give considerable variation to the end product, the main characteristic determinant is the kind of flour (or rubber) used. This chapter examines briefly the chemical structure properties of polymers used in compounding. For compounding skill, some understanding of the foregoing polymer properties is required, especially as they relate to the rubbers being used in the plant. Natural rubber has been modified in many ways since the establishment of a continuous supply of plantation rubber. Some of these modifications, such as chlorinated rubber, have passed their peak of acceptance as other materials supplanted them. A comparatively new modification of natural rubber produced in commercial quantities is epoxidized natural rubber (ENR). Technically speaking, synthetic polyisoprene is a close match for natural rubber. Because of its cost, it has not supplanted natural to any significant extent.
