Design of epoxy resin with sustainability, high adhesion and excellent flame retardancy based on bio-based molecules

The preparation of bio-based epoxy resin with excellent thermal properties and flame retardant properties from green renewable resources had attracted extensive attention in recent years. Starting from the driving structural properties, the purpose of this study is to prepare multifunctional triglycidylester- diphenolic acid- bio-based epoxy (TDBE) with diphenolic acid (DPA), triglycidyl isocyanurate (TGIC), and 9,10-dihydro-9-oxa-10-phosphophenanthrene 10 oxide (DOPO) as raw materials. TDBE/DDM and bisphenol A epoxy resin curing agent (DGEBA/DDM) was prepared with 4,4 '- diaminodiphenylmethane (DDM) as curing agent. TDBE/DDM has excellent fire safety. LOI value rose from 24.5 to 42.0%, and the UL-94 test level passes V-0 level. In the cone calorimeter test, the peak heat release rate (pHRR) is decreased by 69.3%. Besides, the lap shear TDBE adhesive strength was 42.9 MPa, which increased by 62.5%. This new multifunctional bio-based flame retardant epoxy resin provides a broader application prospect for high-performance materials. Graphical Abstract