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