- Rubber technology
Rubber technology is the subject dealing with the transformation of
rubber s orelastomer s into useful products, such asautomobile tire s.The materials includeslatex ,natural rubber ,synthetic rubber and other polymeric materials, such asthermoplastic elastomer s.Vulcanization
Most rubber products are
vulcanized , a process which involves heating with a small quantity of sulphur (or equivalentcross-linking agent so as to stabilise the polymer chains, over a wide range of temperature. This discovery was made byCharles Goodyear in the 1844, but is a process restricted to polymer chains having adouble-bond in the backbone. Such materials includenatural rubber andpolybutadiene . The range of materials available is much wider however, since all polymers become elastomeric above theirglass transition temperature . However, the elastomeric state is unstable because chains can slip past one another resulting in creep orstress relaxation under static or dynamic load conditions. Chemical cross links add the stability to the network that is needed for most practical applications.Processing of Rubber
Methods for processing rubber include
mastication andcalendering , both processes being essential to bring crude rubber into a state suitable for shaping the final product. The former breaks down the polymer chains, and lowers theirmolecular weight so thatviscosity is low enough for further processing. After this has been achieved, various additions can be made to the material ready for cross-linking.
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