Rationalised 2023-24
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Chemistry
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Electronically conducting polymers – In 1977 MacDiarmid, Heeger and Shirakawa discovered that acetylene gas can be
polymerised to produce a polymer, polyacetylene when exposed to vapours of iodine acquires metallic lustre and
conductivity Since then several organic conducting polymers have been made such as polyaniline, polypyrrole and
polythiophene These organic polymers which have properties like metals, being composed wholly of elements like
carbon, hydrogen and occasionally nitrogen, oxygen or sulphur, are much lighter than normal metals and can be used
for making light-weight batteries Besides, they have the mechanical properties of polymers such as flexibility so that
one can make electronic devices such as transistors that can bend like a sheet of plastic