BaTiO3/Polyurethane Dielectric Composites with Diels-Alder Bond for Improved Self-Healing Properties

In general, self-healing dielectric composites are mainly composed of polar hydrogen bonds, which have high hydrophilicity and are unsuitable for humid environment. Dielectric composite with Diels-Alder (D-A) bond contains covalent bonds, it can be adopted as an efficient self-healing material. Here, we construct self-healing barium titanate (BT)/polyurethane (PU) dielectric composites by adopting PU with D-A bond as matrix (BT/PU-DA). The prepared 10% BT/PU-DA composite exhibits superior self-healing ability than that of PU-DA. Moreover, its dielectric constant can reach 9.3 with a loss of only 0.04 at 1000 Hz and maintain 93% repair efficiency of tensile strength. The experimental analysis suggests the introduction of D-A bond can enhance the thermostability and self-healing ability of BT/PU-DA composite. In addition, the incorporation of BT nanopartides and D-A bond in the self-healing composite contributes to the lower dielectric loss and excellent tensile strength after healing. The adopted strategy is a promising and facile approach to develop highly efficient self-healing dielectric material, which will be conducive to reuse and sustainable development of the electronic packaging material in aqueous medium or wet environment.