Synthesis and curing properties of fluorinated curing agent for epoxy resin based on natural soybean isoflavones

A novel fluorinated diamine curing agent (AFPCO) was synthesized from natural isoflavone daidzein , used to cure hydrogenated epoxy resin (DGEHBPA) and tested against commercially available DGEHBPA cured with 4,4′-diaminodiphenylmethane (DDM). The results show that the non-isothermal curing reaction kinetics study found AFPCO to be less reactive than DDM. Compared to DDM, the AFPCO cured material increases the energy storage modulus , impact strength and flexural strength by 34%, 51% and 12% respectively. The AFPCO cured material performs worse in terms of decomposition temperature , but the residual carbon rate exceeds that of DDM/DGEHBPA by 230% and the flame retardancy reaches VL-94 V-1 level. In contrast to the hydrophilic nature of the material after DDM curing, the introduction of fluorine in AFPCO gives the material a water contact angle of 92.19°, which meets the criteria for hydrophobic materials. In contrast to low dielectric constant resins prepared with conventional fluorinated curing agents, AFPCO/DGEHBPA has a high dielectric constant , but still exhibits a low numerical value of 0.0338 in dielectric loss.