Ultrastrong, High Fire Resistance, Repairable, and Recyclable Fluorinated Biobased Polyimine Networks

Traditional commercial thermosetting materials are currently facing significant challenges in terms of reprocessing, degradation, and recycling because of a large demand of petroleum resources, leading to a significant environmental burden. In our work, a trialdehyde monomer synthesized by a renewable resource reacted with 1,4-Bis(4-amino-2-trifluoromethylphenoxy)benzene and 1,4-Bis(4-aminophenoxy)benzene to form a dynamic cross-linked network called BQPs. The fluorinated biobased polyimine material exhibits exceptional mechanical properties with a tensile strength of 96.2 MPa, which is much higher than commercial plastics such as polycarbonate (∼65 MPa). Moreover, it demonstrates excellent flame retardancy by achieving a level of V0 rating in the UL-94 test and a value of 50% in the limiting oxygen index test. Additionally, it can be easily reprocessed within 10 min at high temperature (160 °C) and rapidly repaired with a solvent. Overall, this high-performance fluorinated biobased polyimine product will significantly contribute to expanding the development of polyimine materials.