Plastics are widely used as they have many useful properties. Most plastics and synthetic fibres are made from chemicals derived from crude oil and are made up of long chain molecules called polymers.
Polymers are not simply an invention of chemists. Many are synthesised in nature and even in our bodies. The most common natural polymers are carbohydrates like starch and proteins.
Starch
Starch is a natural condensation polymer made from glucose monomers