Study on effect of crosslink structure on decomposition of epoxy resins in nitric acid

One chemical approach using nitric acid as the solvent to decompose thermosetting epoxy resin was discussed. The samples were prepared by using different kinds of curing agents, namely polyamide （PA651）, isophorone diamine （IPDA）, 4,4＇-diaminodiphenylmethane （DDM） and 2-ethyl-4-methy-imidazole （EMI-2,4） and different kinds of epoxy resins, namely bisphenol-A epoxy resin（E-44）, bisphenol-A epoxy resin（E-51）, N,N,N＇,N＇ teraglycidy 4,4＇ diaminodiphenyl methane （AG-80） and diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate （TDE-85）. Their effects on decomposition rate were investigated and the decomposition products were analyzed by Infra-red （IR） spectra, and Gas Chromatography-Mass Spectrometry （GC-MS）. Based on conclusions drawn from experiments, the mechanism of degrading thermosetting epoxy resin with nitric acid was envisaged tentatively.