Slide-ring gels are interesting model networks where polymer chains are connected through pairs of short cyclic molecules (typically cyclodextrine) that can slide along all of the contour of the chain up to the bulky end-groups that prevent detachment as sketched in the. Figure. In a current Ph.D. thesis, model systems combining sliding rings and elastic polymers are analyzed analytically and numerically to develop the basic know-how to model elastic networks with sliding junctions.
Of major interest is the unexpected sign of the second Mooney coefficient that indicates a strain hardening process as dominant correction to the phantom modulus. This is in contrast to entangled networks, where strain softening is the dominating correction. This disagreement is certainly surprising, since slide ring gels have been discussed as model systems for entangled networks. Besides this open question we are interested in how stress can be redistributed inside a network and how a slide-ring gel may be modified to provide elastic model networks with a zero second Mooney coefficient over a wide range of parameters.
- Müller, T.; Sommer, J.-U. ; Lang M.,
Tendomers – force sensitive bis-rotaxanes with jump-like deformation behavior
Soft Matter 15 (2019), 3671-3679.