The term plastic refers to any material that can be shaped or molded. In this sense, ordinary clay or a soft wax is a plastic material. Perhaps more commonly, plastic has become the term used to describe a class of synthetic materials more accurately known in chemistry as polymers. Some common examples of plastics are the polyethylenes, polystyrenes, vinyl polymers, methyl methacrylates, and polyesters. These synthetic materials may or may not be "plastic" in the pliable sense.

Research on plastic-like materials began in the mid-nineteenth century. At first, this research made use of natural materials. Credit for discovery of the first synthetic plastic is often given to the American inventor, John Wesley Hyatt. In 1869, Hyatt was awarded a patent for the manufacture of a hard, tough material made out a natural cellulose. He called the product "celluloid."

It was not until 1907, however, that an entirely synthetic plastic was...