Now Thermoplastics are polymer plastics which turn soft on heating and become hard on cooling. Natural rubber on undergoing vulcanization is said to be a thermosetting polymer. Vulcanization is basically a chemical process where the physical properties of rubber are improved. Neoprene is a thermoset or thermosetting material not a thermoplastic material. Being in the category of thermoplastic, Teflon is used for non- stick cookware and Polystyrene finds its use in CD cases and domestic appliances.