Plastics are man-made materials that can be shaped into almost any form.  They are one of the most useful materials ever created.  Our homes, schools, and businesses are filled with plastic products.  Engineers have developed plastics that are as rigid as steel or as soft as cotton.  They can make plastics that are any color of the rainbow--or as clear and colorless as crystal.  Plastics can be rubbery or rigid, and they can be shaped into an endless variety of objects, ranging from automobile fenders to squeezable bottles to soft fabrics.  Plastic products, especially those used by industries, often have a useful life of many years. 

Plastics consist of long chains of molecules called polymers.  These chains are made of repeating patterns of smaller molecules.  Each of the smaller molecules forms a "link" in the polymer's chain.  In some plastics, the chains are rigid and are lined up like logs flowing down a river.  In others, they are flexible and tangled like spaghetti on a plate.  These different structures give plastics their most notable characteristic, the ability to be shaped.  In fact, the word plastics comes from the Greek word plastikos, which means able to be shaped. 

As useful as they are, plastics do have drawbacks.  The biggest problem is that most plastics take a very long time to decompose (break down into simple compounds).  Figuring out how to dispose of plastic wastes has become a major environmental concern.


For thousands of years, people used natural gums and resins with properties similar to plastics.  For example, the ancient Greeks and Romans created decorative objects from amber, a fossil resin.  During the Middle Ages, Europeans used the natural resin lac, and its purified form, shellac, to coat objects. 

By the mid-1800's, the commercial molding of plasticslike natural substances had developed.  Manufacturers molded items from lac, gutta-percha (a tree resin), and other substances obtained from animal, vegetable, and mineral sources.  Products made from these natural "plastics" included brush handles, knobs, electrical insulation, phonograph records, and novelty items.  Museums and collectors treasure the beautiful molded objects created during the late 1800's and early 1900's. 

Despite their beauty, these natural molding materials had several disadvantages.  Manufacturers often had difficulty obtaining the raw materials.  Some materials proved difficult to mold, and many of the finished products turned brittle and broke easily.