= Solution
<DMSO> is a strong hydrogen-bond acceptor. It competes for the NH donors of the <UPy units> and solvates the association sites, weakening their mutual hydrogen bonding.
For A, \b[the intermolecular chains should shorten or dissociate], reducing the association-driven <viscosity>. For B, \b[the intramolecular ring should become less populated], increasing the fraction of open <conformations>. Sufficient <DMSO> also weakens rings of A and any intermolecular associations of B. The covalent molecular skeletons remain intact.
The extent depends on <DMSO> fraction and the association <free energies> in the mixed <solvent>. <solvent> <viscosity> itself also changes, so the prediction concerns the supramolecular contribution rather than an unconditional numerical value for total solution <viscosity>.
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