Nomenclature of step-growth polymers

The name is based on a presence of two subunits. Note that the carbonyl oxygen is called an 0x0 substituent. In addition, the presence of a 1-oxo substituent requires that parentheses enclose the subunit. 

Physical properties of polymers are influenced by the sizes of the molecules and by the nature of the primary and secondary bond forces. They are also influenced by the amount of symmetry or uniformity in molecular structures, and by arrangements of the macromolecules into amorphous or crystalline domains. This affects melting temperatures, solubilities, melt and solution viscosities, tensile strengths, elongation, flexibility, etc.  

Due to the large sizes of the polymer molecules, the secondary bond forces assume much greater roles in influencing physical properties than they do in small organic molecules. These secondary bond forces are van der Waal forces and hydrogen bonding. 

The van der Waal forces can be subdivided into three types dipole-dipole interactions, induced dipoles, and time-varying dipoles. 

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