We begin the chapter by stating the obvious: Plastics are all around us. After considering a few examples, we relate plastics with polymers — materials whose molecules consist of long chains of atoms. Polymers can be natural or synthetic. Here we are more concerned with the latter, particularly the six polymers we normally encounter, the "Big Six," and their impact on the American economy, lifestyle, and leisure. Chemists alter the properties of polymers by modifications in molecular structure and choice of monomers, the building blocks of polymers. To explain the chemistry of how polymers are made, we consider polymerization by addition and condensation reactions. A short, but significant, aside addresses proteins, an important class of natural polymers, and nylon, a related synthetic polymer. Because polyethylene is the simplest and most widely used plastic, we look at it in some detail. Its composition, structure, production, properties, modifications, and uses are all considered.

The phenomenal success of plastics and their widespread distribution has not been without cost. Therefore, the final third of the chapter is devoted to the problems associated with what to do with plastic articles after we are done using them. The issue of plastic versus paper supermarket bags provides a focus and a brief case study. We examine disposal options including incineration, biodegradation, reuse, recycling, and source reduction. Not surprisingly, we find that there are no easy solutions to the problems posed by plastics, these useful and ubiquitous materials.