Rheology of vitrimers

We describe the full rheology profile of vitrimers, from small deformation (linear) to large deformation (non-linear) viscoelastic behaviour, providing concise analytical expressions to assist the experimental data analysis, and also clarify the emerging insights and rheological concepts in the subject. We identify the elastic-plastic transition at a time scale comparable to the life-time of the exchangeable bonds in the vitrimer network, and propose a new method to deduce material parameters using the Master Curves. At large plastic creep, we describe the strain thinning when the material is subjected to a constant stress or force, and suggest another method to characterize the material parameters from the creep curves. We also investigate partial vitrimers including a permanent sub-network and an exchangeable sub-network where the bond exchange occurs. In creep, such materials can exhibit either strain thinning or strain thickening, depending on applied load, and present the phase diagram of this response.

Automated summary

In this paper, we provide a comprehensive description of the rheological behavior of vitrimers, ranging from small deformation to large deformation. We propose concise analytical expressions to assist in data analysis and clarify emerging insights and concepts in the field. Additionally, we identify the elastic-plastic transition at a timescale comparable to the lifetime of exchangeable bonds in the vitrimer network and propose a new method to deduce material parameters. Furthermore, we investigate partial vitrimers and present a phase diagram of their strain response under different applied loads.