Modification of bisphenol a type epoxy resin by biobased magnolol epoxy

Reducing the dependence of epoxy resin preparation on petroleum resources and developing thermosetting epoxy resins with excellent comprehensive performance are important directions for the current development of epoxy resins. This article uses biomass resource magnolol as the main raw material to prepare magnolol epoxy monomer (DGEM). Then, using 4,4-diaminodiphenylmethane (DDM) as the curing agent, the DGEM and bisphenol A epoxy resin (E44) were blended and cured. The results showed a dual modification effect of DGEM on the toughening and strengthening of E44 epoxy resin. When the mass ratio of DGEM to E44 is 30:70, the bending strength of the cured blended resin is 18.7% higher than that of the E44 system, and the tensile strength is 57.7% higher. When the mass ratio of DGEM to E44 is 5:95, the cured blended resin exhibits the optimal impact strength (5.10 kJ/mol), which is 22.9% higher than the pure E44 system. However, the addition of DGEM reduced the glass transition temperature and crosslinking degree of the blended resin system. The addition of DGEM improves the heat resistance and flame retardancy of the blended resin. When the mass ratio of DGEM: E44 was 50:50, the vertical combustion reached UL-94 V-0 level.