Hexahydrotriazine derivative containing imidazole for fast curing, improved mechanical strength, and flame retardancy of epoxy

摘要

We synthesized a hexahydrotriazine derivative containing imidazole, 1,3,5-tris[4 '-(1H-imidazol-1-yl)-(1,1 '-biphenyl)-4-yl]-1,3,5-triazinane (HIM) and adapted it as a co-curing agent for epoxy resin (EP). The curing kinetics of HIM were evaluated using elevated differential scanning calorimetry (DSC) analysis, and the curing speed was determined to be accelerated with HIM. Moreover, when 5 phr of HIM was applied to the epoxy system, the tensile strength of cured EP increased to 50.9 MPa. Because of the high nitrogen content of HIM, when the candidate amount of HIM was increased, the char yield increased. HIM (20 phr) showed a char yield of 36.1%, which is about 74% higher than that of the HIM (0 phr) reference (20.7%). The char layer acts as a barrier between oxygen and polymeric decomposition gases, inducing a high flame-retardant property.