Introduction

Abstract

Natural rubber has been an essential commodity not only for the tyre industry but also for more than 50,000 products that hold elasticity as an attribute. Rubber is obtained from the exudates of certain tropical plants (natural rubber) or derived from petroleum and natural gas (synthetic rubber). Because of its elasticity, resilience and toughness (Table 1.1), rubber is the basic constituent of tyres used in automotive vehicles, aircraft and bicycles. A car has almost 30% of its components made of rubber. The prime source of natural rubber worldwide is Hevea rubber or Hevea brasiliensis. Some of the alternate sources of rubber are: Manihot glaziovii (Ceara rubber), Manihot dichotoma (Jeque rubber), Castilla elastica (Panama rubber), Ficus elastica (India rubber), Funtimia elastica (Lagos rubber), Landolphia kirkii (Landolphia rubber), Cryptostegia grandiflora and C. madagascariensis (Madagascar rubber), Parthenium argentatum (guayule rubber), Taraxacum kok-saghys (Russian dandelion) (Table 1.2).