ABSTRACT
Polymer molecules are chains of covalently bonded monomer units. Some polymers are linear, like beads on a necklace; others are branched. For predicting the properties of all types of polymers, statistical mechanics plays a key role because of two intrinsic polymer distribution functions. First, synthetic polymers have distributions of chain lengths. Second, polymer chains have distributions of conformations. Many of the unique properties of polymeric solutions and solids, such as the elasticity of rubber and the viscoelasticity of slimy liquids, are consequences of the entropies that arise from the conformational freedom of chain molecules. A polymer molecule can be composed of up to tens of thousands of monomers. Because each chain monomer is about the size of a solvent molecule, a polymer molecule occupies much more volume than a solvent molecule. That makes the volume fraction of a polymer in solution very different from its mole fraction.
