Polymer

A polymer is a chemical compound formed by the linking of many smaller molecules (particles) into a long chain. Polymers can be both natural and synthetic, and most living things are composed of natural polymers. Polymers can store energy and information and have structural uses as well.

In Greek, a polymer has many (polys) parts (meros). It is an organic compound or a natural substance containing carbon that is made up of many smaller repeating parts, or units, called monomers. Polymers play an important role in the chemistry of life, and without chemicals and chemical reactions, there would be no living things. Since they are compounds or are made up of many smaller units, polymers are also called macromolecules (meaning they are giant molecules). A polymer is also described as a "chain" molecule since the smaller units that make it up are linked together like a long chain. Polymers are so useful because although this chain has only a certain length, it can, like a piece of string, be tied and twisted and turned into all sorts of different shapes. Polymers combine flexibility with strength since their chains can be stretched several times their normal length without breaking. It is no surprise therefore that examples of substances composed of natural polymers would be starch, wool, and rubber.

Without polymers there would be no plants or trees since cellulose is a polymer. Plants use cellulose to build their cell walls, and trees use it to make their woody parts. Green plants also store their food as starch, which is a polymer. Proteins are another type of polymer, and wool is a variety of protein, as are the life-coding molecules of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It could be said that life on Earth is based to a great degree on the existence, properties, and reactions of two classes of polymers—proteins and nucleic acids.

Aside from these organic forms of polymers, there are inorganic polymers and synthetic polymers. Since an organic compound is a chemical compound that contains carbon, an inorganic compound is one that does not have any carbon in it. Most of the inorganic polymers that are found in nature are typically very hard and strong. Many minerals, like diamond, quartz, and silica, are inorganic polymers. Synthetic polymers or polymers that are made by people can be organic (as with rubber that occurs both naturally and as a human-made product), or inorganic (like plastics and adhesives). Once chemists understood the process of polymerization or synthetic creation of polymers, they were able to produce everything from vinyl, polyurethanes, and silicones and to vary their properties in ways that exceeded even what nature could produce.