INDUSTRIAL POLYMERS, CHEMISTRY OF

structure and composition of chemical compounds made up of long, chainlike molecules. What distinguishes polymers from other types of compounds is the extremely large size of the molecules. The size of a molecule is measured by its molecular weight, which is equal to the sum of the atomic weights of all the atoms that make up the molecule. Atomic weights are given in atomic mass units; in the case of water, for example, a single water molecule, made up of one oxygen atom (16 atomic mass units) and two hydrogen atoms (1 atomic mass unit each), has a molecular weight of 18 atomic mass units. Polymers, on the other hand, have average molecular weights ranging from tens of thousands up to several million atomic mass units. It is to this vast molecular size that polymers owe their unique properties, and it is the reason that the German chemist Hermann Staudinger first referred to them in 1922 as macromolecules, or giant molecules. The atoms composing macromolecules are held together by covalent chemical bonds, formed by the sharing of electrons. Individual molecules are also attracted to one another by electrostatic forces, which are much weaker than covalent bonds. These electrostatic forces increase in magnitude, however, as the size of the molecules increases. In the case of polymers, they are so strong that agglomerates of molecules can be molded into permanent shapes, as in the case of plastics, or drawn out into fibres, as in the textile industry. The chemical composition and structure of polymers thus make them suitable for industrial applications. The distinctive properties of polymers and their formation from chemical precursors are the subject of this article. The information provided here, it is hoped, will enable the reader to proceed with a fuller understanding to separate articles on the processing of plastics, elastomers (natural and synthetic rubbers), man-made fibres, adhesives, and surface coatings. Additional reading Jacqueline I. Kroschwitz (ed.), Encyclopedia of Polymer Science and Engineering, 2nd ed., 17 vol. (198590), is the most comprehensive source of information on polymer science and includes articles on the major topics treated in this article; it is also available in a condensed, 1-vol. edition, Concise Encyclopedia of Polymer Science and Engineering (1990). Two additional reference works are Geoffrey Allen and John C. Bevington (eds.), Comprehensive Polymer Science: The Synthesis, Characterization, Reactions & Applications of Polymers, 7 vol. (1989); and Joseph C. Salamone (ed.), Polymeric Materials Encyclopedia, 12 vol. (1996). Books on polymer science for the nonscientific reader are Hans-Georg Elias, Mega Molecules (1987; originally published in German, 1985); and Raymond B. Seymour and Charles E. Carraher, Giant Molecules: Essential Materials for Everyday Living and Problem Solving (1990).Textbooks with overviews of polymer science include K.J. Saunders, Organic Polymer Chemistry: An Introduction to the Organic Chemistry of Adhesives, Fibres, Paints, Plastics, and Rubbers, 2nd ed. (1988); Harry R. Allcock and Frederick W. Lampe, Contemporary Polymer Chemistry, 2nd ed. (1990); Malcolm P. Stevens, Polymer Chemistry: An Introduction, 2nd ed. (1990); George Odian, Principles of Polymerization, 3rd ed. (1991); and Seymour/Carraher's Polymer Chemistry: An Introduction, 4th ed., rev. and expanded by Charles E. Carraher (1996). Considerable information on the physics or engineering aspects of polymer science is found in Fred W. Billmeyer, Jr., Textbook of Polymer Science, 3rd ed. (1984); R.J. Young and P.A. Lovell, Introduction to Polymers, 2nd ed. (1991); J.M.G. Cowie, Polymers: Chemistry and Physics of Modern Materials, 2nd ed. (1991); Paul C. Painter and Michael M. Coleman, Fundamentals of Polymer Science: An Introductory Text (1994); and Arthur E. Woodward, Understanding Polymer Morphology (1995).Herbert Morawetz, Polymers: The Origins and Growth of a Science (1985, reissued 1995); and Raymond B. Seymour and Gerald S. Kirshenbaum (eds.), High Performance Polymers: Their Origin and Development (1986), a set of conference papers, both describe the historical development of polymer chemistry. Paul J. Flory, Principles of Polymer Chemistry (1953, reissued 1990), is a classic text that has withstood the test of time. Roy W. Tess and Gary W. Poehlein (eds.), Applied Polymer Science, 2nd ed. (1985), covers the chemistry and applications of most commercially important polymers. Henri Ulrich, Introduction to Industrial Polymers, 2nd ed. (1993), succinctly outlines the processing and marketing of important industrial polymers. Malcolm P. Stevens