Dynamic Cross-Linking\nChemistry Enables Advanced One-Component\nThermosets

This work discloses a new strategy based on dynamic cross-linking\nchemistry to achieve advanced one-component thermosets combining ultralong\nstorage life and fast cross-linking. One-component thermosets containing\nresin and cross-linker in one pot have the features of simple operation,\nstable quality, and low waste; however, an urgently needed one with\nlong storage life at room temperature and fast cross-linking at medium–low\ntemperatures (≤130 °C) remains an enormous challenge.\nHerein, we innovatively propose a strategy of dynamic cross-linking\nand controlled dissolution to address this issue. As an example, a\ndynamic cross-linked cross-linker (DCC) is synthesized via Diels–Alder\nreaction to hide the high activity of a commercial amine-type cross-linker.\nA one-component thermoset from a DCC and a commercial diepoxy monomer\ncan be stored for an ultralong time at room temperature and cross-linked\nrapidly below 130 °C. Moreover, the DCC can also serve as a latent\naccelerator for epoxy/anhydride thermosets with the same storage life\nas the control system with no accelerator at room temperature and\nfast cross-linking at elevated temperatures. This work is beneficial\nfor promoting the application of dynamic cross-linking chemistry and\nmeeting the urgent need for advanced one-component thermosets in the\nfields of advanced composites, coatings, electronic packaging materials,\nautomotive and electronic adhesives, etc.