self healable diels-alder crosslinked polyurethane elastomers based on furane modified calix[4]arene

Self-healing polymers can restore their performance after inevitable damage and are promising in the industry owing to their longer service life and lower repair cost. in this study, a series of polyurethane (pu) elastomers (pu-c4aα-da) were synthesized through diels-alder reactions using different molar ratio of p-tert-butyl calix[4]arene bearing furane groups (c4a-fa) as a new chain extender and a bismaleimide (bmi) polyether amine as a diels-alder cross-linking agent. the tensile and tga results show an improvement in the thermal and mechanical properties of the polymers by increasing the content of da bonds. the retro-da reaction phenomenon in the synthesized pu-c4aα-da is explained by the existence of a broad dsc endothermic peak from 80 to 140°c (centering at 115°c). the healing efficiency of pu-c4a15-da obtained 92.5% (measured by tensile test), which is the highest value among self-healing pus reported in the literature