Introduction to polymers, which "are macromolecules -- in other words, they are really big molecules. ... Some polymers occur naturally, such as starch, protein, and cellulose." In the 19th century, "chemists began to synthesize polymers in the lab. These [synthetic] polymers ... can be found in everything from plastic bags to rubber tires," and include materials such as "nylon, rayon, vinyl, [and] Teflon." This site includes a timeline, information about chemists working with polymers, and links to related resources.