Networks Containing No Flexible Spacers

Networks containing no flexible spacers are divisible into two classes (a) networks with stiff, rigid or wormlike, mesogenic segments connected by either rigid or flexible branchpoints, and (b) networks in which the polymeric 

In group (a), rigid branchpoints may be as simple as the 1,3,5-benzenetriamide residue  

Flexible junctions may be as simple as the tricarballylic amide residue to be discussed in Sect. 3.2.2, or as complex as the cyclic penta(methysiloxane) group recently described by Pachter et al. [150]. Poorly defined flexible junctions are claimed in the patent literature and will be discussed below when appropriate. In group (b), long alkylene chains holding together stiff chains, are typical. 

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