Introduction

Abstract

A polymer is a large molecule consisting of monomers that are tied together by chemical bonds. The monomers can be either small units (such as CH2 in polyethylene; see Fig. 1.1) or larger units with an internal structure (such as the adenine-thymine and cytosine-guanine base pairs in the DNA double helix; see Fig. 1.2). Polymers abound in nature because of the multivalency of atoms like carbon, silicon, oxygen, nitrogen, sulfur and phosphorus, which are capable of forming long concatenated structures.