Chapter 2
Structure–Property Relationships
2.1 Characterization of Chemical Structures..................
Polymer chain structures include the chemical structures (known as primary
structures) and conformation structures (known as secondary structures and further
assembly structures). We first introduce the characterization of chemical structures
of polymer chains, followed in the next chapters by the Gaussian treatment of their
ideal-chain conformations and by the scaling analysis of their non-ideal-chain
conformations, respectively. The conformations of self-assembled block copolymers
as well as the conformations of crystalline polymers will be introduced in Chaps. 9 and
10 , respectively.
The relationship between chemical structures and their physical performance is
one of the central topics of polymer physics. IUPAC has recommended a whole set
of names to describe the detailed chemical structures of polymer chains and their
derivatives. However, in our daily communication, people prefer to use the popular
names of polymers reflecting their characteristic physical performances, such as
high-density polyethylene (HDPE), foamed polystyrene, thermoplastic elastomers,
liquid crystal polymers, conductive polymers, and polyelectrolyte. Such terminology
allows us to comprehend quickly the basic characteristics of chemical structures
responsible for their specific physical properties.
In fact, as long as we have obtained a polymer sample, we need first to determine
its basic physical properties. The determination mainly relies on the key informa-
tion about the chemical details of that sample. In other words, we need to carry out
the necessary characterization of the chemical structures of polymer chains. Here
rises a question, what are the essential factors characterizing the chemical structures
of polymer chains, from which we can make a proper speculation on the funda-
mental physical properties?
To answer the question above, we shall begin with an analogy to the characteri-
zation of a single crystal, for example, a piece of diamond. First, the single crystal
possesses intrinsic structuralsymmetry. For diamond, thesp^3 hybrid orbits of the
carbon atoms lead to a tetrahedral structure for the most stable packing of carbon
W. Hu,Polymer Physics, DOI 10.1007/978-3-7091-0670-9_2,
#Springer-Verlag Wien 2013
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