In various industrial fields, plastic are widely used. You can see plastic seals in garment accessories, different toys which are made of plastic, plastic chairs in public etc. How is the plastic developed?

Early plastics were bio-derived materials such as egg and blood proteins, which are organic polymers. Treated cattle horns were used as windows for lanterns in the Middle Ages. Materials that mimicked the properties of horns were developed by treating milk-proteins with lye. In the 1800s the development of plastics accelerated with Charles Goodyear's discovery of vulcanization as a route to thermo-set materials derived from natural rubber. Many storied materials were reported as industrial chemistry was developed in the 1800s. In the early 1900s, Bakelite, the first fully synthetic thermo-set was reported by Belgian chemist Leo Baekeland. After the First World War, improvements in chemical technology led to an explosion in new forms of plastics. Among the earliest examples in the wave of new polymers were polystyrene (PS) and polyvinyl chloride (PVC which are widely used to make plastic seals, bags). The development of plastics has come from the use of natural plastic materials (e.g., chewing gum, shellac) to the use of chemically modified natural materials (e.g., rubber, nitrocellulose, collagen) and finally to completely synthetic molecules (e.g., bakelite, epoxy, polyvinyl chloride).

The plastic material, parkesine, was patented by Alexander Parkes, In Birmingham, UK in 1856. It was unveiled at the 1862 Great International Exhibition in London. Parkesine won a bronze medal at the 1862 World's fair in London. Parkesine was made from cellulose (the major component of plant cell walls) treated with nitric acid as a solvent. The output of the process commonly known as cellulose nitrate or pyroxilin could be dissolved in alcohol and hardened into a transparent and elastic material that could be molded when heated, and plastic seals are made like this by mold. By incorporating pigments into the product, it could be made to resemble ivory.