Cross-Linking Behavior of Diskotic Side-Chain Polymers in Solution

Abstract

The cross-linking behavior for a series of solutions of closely related diskotic side-chain polymers, differing in the tails of the mesogens, has been studied. Solubility parameters are used to describe the driving force for the cross-linking behavior in these solutions. Complex formation enthalpies of the physical networks as determined by dynamic rheological measurements in combination with a statistical network model are relatively low. Moreover, with a statistical theory for equilibrium polymers, used by Cates and Candau for slightly similar systems, an average number of disks in a cross-link is calculated. Only two disks appear to be incorporated in the majority of cross-links, whereas most of the disks are in a free state.

Unidirectional Dimerization and Stacking of Ureidopyrimidinone End Groups in Polycaprolactone Supramolecular Polymers

“…In the case of the decameric stack ( f = 20), a interaction energy of (−9.3/9 =) −1.03 kJ/mol per pair is calculated. Furthermore, the rather low (absolute) value of −6.4 kJ/mol is of the order of the interaction energy between benzene rings and also of the order of the interaction energy between mesogenic groups in discotic side chain liquid crystalline polymers. , Hence, it is not unreasonable to attribute the cross-link formation to the interaction between UPy dimers, which self-assemble into small (dimeric) stacks. Small aggregates of poly(THF) functionalized with modified adenine were shown to be responsible, in combination with phase separation, for the formation of a temperature-dependent physical network with a relatively high plateau modulus .…”

On the nature of crosslinks in thermoreversible gels

“…in our case for many discs in a column), whereas in the present case this number is presumably very small. Consequently the integral was replaced by a summation [65,68]. Results of calculations are presented in Table 2.…”

“…The conclusion is that the average functionality of the crosslinks in these gels will be slightly above 4. The formation enthalpy, ΔH c , of a crosslink can be calculated from the temperature dependence of the plateau value of the storage modulus [65,68]. Results are given in Table 3.…”