The Science of Rubber Compounding

This chapter discusses the science and different processes related to rubber compounding. Compounding is a complex multidisciplinary science necessitating knowledge of materials physics, organic and polymer chemistry, inorganic chemistry, and chemical reaction kinetics. Compounded rubber has many unique characteristics not found in other materials, such as dampening properties, high elasticity, and abrasion resistance. Hence, rubber has found use in applications such as tires, conveyor belts, large dock fenders, building foundations, automotive engine components, and a wide range of domestic appliances. Natural rubber is available in three basic types: technically specified rubbers, visually inspected rubbers, and specialty rubbers. Natural rubber usage has increased substantially in modern radial tires. The Rubber Manufacturers Association has a further set of standards for quality and packing of latex natural rubber grades. The classification of synthetic rubber is governed by the International Institute of Synthetic Rubber Producers (IISRP). Calcium carbonate is used as low-cost filler in rubber products for static applications such as carpet underlay. Titanium dioxide finds extensive use in white products such as white tire sidewalls where appearance is important.