Crack velocity dependent toughness of polyrotaxane networks: The sliding dynamics of rings on polymer under stretching

摘要

We investigate the fracture toughness of slide-ring (SR) gels, in which polymer chains are cross-linked by ring molecules, at various strain rates to evaluate the sliding speed of the cross-linking points. SR gels show a drastic decrease of the fracture energy at crack velocities higher than a critical value, since the sliding motion of the rings cannot catch up with the high deformation rates. From the critical transition velocity, we estimated the characteristic time scale of the sliding dynamics to be micro-seconds under the single-layer fracture assumption.