Polymer science be considered polymer science in the modern sense. In the 1840s, Friedrich Ludersdorf and Nathaniel Hayward independently discovered that adding sulfur to raw natural rubber (polyisoprene) helped prevent the material from becoming sticky. In 1844 Charles Goodyear received a U.S. patent for vulcanizing natural rubber with sulfur and heat. Thomas Hancock had received a patent for the same process in the UK the year before. This process strengthened natural rubber and prevented it from melting with heat without losing flexibility. This made practical products such as waterproofed articles possible. It also facilitated practical manufacture of such rubberized materials. Vulcanized rubber
Rubber technology 1844, but is a process restricted to polymer chains having a Double bond in the backbone. Such materials include natural rubber and polybutadiene. The range of materials available is much wider however, since all polymers become elastomeric above their Glass transition temperature. However, the elastomeric state is unstable because chains can slip past one another resulting in creep or stress relaxation under static or dynamic load conditions. Chemical cross links add the stability to the network that is needed for most practical applications. WORKER PROCESSING RUBBER Methods for processing rubber include mastication and various operations like mixing, calendering, extrusion, all