The dissociation of physical interaction clusters under tensile deformation of hybrid double network gels

Abstract

Hybrid double network (DN) gels, including the physical interaction (PI) network and chemically cross-linked (C-CL) network, exhibit superior mechanical behaviors. Herein, the influence of the physical interaction strength and the strain rate on mechanical properties of hybrid DN gels was investigated by exploiting coarse-grained molecular dynamics simulations. The PI network was constructed successfully based on clusters acting as physically cross-linked sites. In the earlier stage, the resistance of clusters to the dissociation mainly caused the increase of the stress. While at larger strains, the soar of the stress was dominated by the stretching of bonds in the C-CL network. It was more difficult to dissociate clusters and stretch bonds with the physical interaction strength increasing. Clusters were broken up and frequently rejoined at lower rates, along with the slight bond stretching. Generally, this work provided the evolution of microstructure in hybrid DN gels, and guided the designing of high-performance polymers.