Impact of hydrogen bonds dynamics on mechanical behavior of supramolecular elastomer

Here our special consideration is devoted to the relationship between dynamics and mechanical behaviours of supramolecular elastomer (SE) based on 2-ureido-4[1H]-pyrimidinone (UPy) groups. We find that SE exhibits a new relaxation mode (alpha' relaxation) which differs from segmental relaxation mode (alpha relaxation) and normal relaxation mode (NM). Calculated by Arrhenius model, supramolecular interactions are much lower than the bonds energy of covalent bonds; this enables high energy dissipation as the elastomer is subjected to deformation. Moreover, unlike covalent bonds, the hydrogen bonds of UPy groups are dynamic and longer waiting time leads to better re-association efficiency, as evidenced by recovery of hysteresis loop during cyclic tensile tests. This work on the relationship between dynamics and mechanical properties will not only improve the understanding of reversible bonds relaxation, but also provide an idea on preparing mechanically robust SE for us. (C) 2016 Elsevier Ltd. All rights reserved.