Hydrogen-bonding liquids amorphous polymers

In the derivation of Eq. (7.3) by Hildebrand only dispersion forces between structural units have been taken into account. For many liquids and amorphous polymers, however, the cohesive energy is also dependent on the interaction between polar groups and on hydrogen bonding. In these cases the solubility parameter as defined corresponds with the total cohesive energy. 

In Equation 5.4, the solubUity parameter is that due to only dispersive force between structural units of the concerned solute and polymer since the original Regular solution theory of Scatchard and HUdebrand was restricted to nonpolar, non-hydrogen bonding solutes-polymer systems. However, for many liquid and amorphous polymers, contribution from polar forces and hydrogen bonding [33] need to be considered. Accordingly, Equation 5.4 becomes... 

Pahnans and Meijer have reported wholly organic supramolecular materials the phase segregation of benzene-1,3,5-tricarboxamide (BTA)-based helical nanorods within an amorphous polymer such as poly(ethylene butylene) (PEB) resulted in elastomeric behavior (Figure 8). The BTA motif has two binding sites (top and bottom face of the discotic), which provide the basis for both supramolecular chain extension and simultaneous cross-linking. Furthermore, hydrogen-bonding interactions and order in the nanofibers were studied via infrared (IR) spectroscopy and circular dichroism (CD). The materials are liquid crystalline at room temperature, which leads to their elastomeric properties. 

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