Chapter 1 - Introduction to plastics, polymers, and their properties

Abstract

This chapter is in several parts starting with an introduction to polymer chemistry. It includes polymerization chemistry and the different types of polymers and how they differ from each other. The following discussed subjects are copolymers, branching, cross-linking, steric hindrance, isomerism, crystallinity, and other factors that affect the molecular structures of the polymers used to make plastics. Since plastics are rarely “neat,” reinforcement, fillers, and additives are reviewed. The influence of molecular structure on properties is examined. A basic understanding of plastic and polymer chemistry makes the discussion of plastics easier to understand, and it also provides a basis for the introductions of the plastic families in later chapters. The testing of plastics is the next part. This section focuses on the basics of plastic properties. It is in several major parts. First, the mechanical testing of plastics including tensile, shear, and flexural properties is covered. Impact tests are discussed next. Thermal properties such as melt index and glass transition temperature are then discussed. The final section is a perspective on how to use the data in plastic selection for specific uses based on thermal and mechanical properties, in the form of selection guides.