The polymers which are prepared in the laboratory are known as synthetic polymers or man-made polymers. A variety of synthetic polymers as plastic (polythene), synthetic fibres (nylon 6, 6) and synthetic rubbers (Buna – S) are examples of manmade polymers extensively used in daily life as well as in industry. Classification of synthetic polymers.
Industrialists, engineers and technologists often classify polymers in other categories based on their properties –
- Thermoplastics are materials that can be softened (melted) by heat and re-formed (moulded) into another shape. Technically, thermoplastics are the materials we call plastics. Familiar examples include polyethylene and nylon.
- Thermoset plastics are materials that melt initially but on further heating become permanently hardened. They cannot be softened and remoulded without destruction of the polymer. Bakelite is an example of a thermoset plastic.
Further classifications can be made based on the degradability of the polymer –