Hexahydro-s-triazine: A Trial for Acid-Degradable Epoxy Resins with High Performance

Hexahydro-s-triazine (HT) derivatives are acid-sensitive compounds. 4,4′,4″-(1,3,5-Hexahydro-s-triazine-1,3,5-triyl) tris(N-(2-aminoethyl) benzamide) (HT-A) bearing three amino groups was synthesized as a curing agent to prepare the acid-degradable epoxy resin. The chemical structures of HT-A and its precursor were confirmed by 1H NMR and 13C NMR. The synthesized HT-A, as well as the commercialized 4,4′-diaminodiphenylmethane (DDM) (for use as the control) were used to cure diglycidyl ether of bisphenol A (DGEBA), respectively. The property examinations performed by dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and tensile test demonstrated that the HT-A-cured epoxy presented high thermal and mechanical properties which were comparable with those of the DDM cured one. Meanwhile, degradation investigation indicated that the HT-A-cured epoxy could be controllably degraded with strong acid stimuli. Thus, HT-A has a great potential to produce recyclable thermosets with satisfactory properties.