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
Ethylene propylene rubber aprotic. Amorphous forms of EPM are flexible at low temperatures (with glass transition points around -60 °C). Via selection of certain sulfur compounds EPM can remain heat resistant up to 130 °C and up to 160 °C with peroxide curing. These two tables contain some of the main properties of EPM. EPM has a large number of uses due to the many ways in which the polymer can be designed, for example; it is used in automotive weather-stripping and seals, self-amalgamating tape, glass run channels, radiators, garden and appliance hoses, tubing, belts, roofing membranes, expansion joints, rubber mechanical goods, plastic