Supramolecular Interactions in the Formation of Thermotropic Liquid Crystalline Polymers - Liquid Crystalline Functional Assemblies and Their Supramolecular Structures - page 121

mesogen-containing polymers as well as supramolecular systems which orga-
nize in solution (lyotropic) and/or in the melt (thermotropic). The purpose of
this paper is to focus on recent developments, which have occurred since the
turn of the century, on the utilization of specific supramolecular interactions
to form polymeric aggregates which exhibit thermotropic LC properties.
1.1
Background on Combining Supramolecular Chemistry
and Liquid Crystallinity
The design of polymeric molecules which combine tailored supramolecular
interactions with liquid crystallinity has been around since the late 1980s
and early 1990s. Pioneering work by Fréchet, Kato [42-45], Lehn [46-50]
and Griffin [51-54], and others during this period demonstrated that specific
supramolecular interactions, in the form of hydrogen bonding, can be used to
access supramolecular LCPs (SLCPs). Figure 2 shows a selection of the early
SLCPs, designed by these groups, in which hydrogen bonding plays an import
role in forming the structure.
Fig. 2 A selection of early examples of supramolecular liquid crystalline polymers de-
signed by Fréchet and Kato [42-45], Lehn [46-50] and Griffin [51-54]
In principle, there are a number of ways that supramolecular chemistry
can be utilized to influence/access LC polymeric systems. One way is to access
different polymeric architectures, such as main-chain, side-chain, or network
structures (Fig. 3). For example, main-chain SLCPs can be formed through the
aggregation of low(er) molecular weight ditopic compounds whose chain ends
interact with each other through specific non-covalent interactions. Concep-
tually, this can occur in a number of different ways. The simplest conceptual