Fig. 6. (a) Arrhenius plots of imine-based vitrimers constituted of diphenylmethane (TFMP-M), dicyclohexylmethane (TFMP-P) and hexamethylene (TFMP-H)-derived building blocks, showing significant change in relaxation times and related activation energy. Adapted with permission from ref. 52. Copyright 2018 American Chemical Society. (b) Stress relaxation recorded for epoxy-based vitrimers possessing different ratio of permanent cross-links. Incomplete relaxation is observed in composition, having more than 20% permanent linkers. Adapted with permission from ref. 54. Copyright 2018 American Chemical Society.