| Owing to its special properties, epoxy resin is widely used in many areas. However, as a kind of cross linking thermosetting resin, epoxy resin cannot be melted as well as dissolved in any common solvent, or even degraded by microorganism so that it is a tough problem to deal with the discarded materials after used.In this paper, a kind of chemical method that uses water as the liquid reaction medium to decompose epoxy resin was studied. The thermosetting epoxy resin was decomposed successfully under the condition of nearcritical water. The effects of different reaction time, different decomposition temperature, pressure, feedstock on the thermosetting epoxy resin E-51/MeHHPA were investigated when the pure water was used as solvent. The decomposition rate rised rapidly as the temperature and reaction time increased. The decomposition rate was not improved remarkably when the feedstock ratio was changed. The volume of water and reaction pressure had great influence on decomposition rate of epoxy resin.The decomposition reaction products were characterized by Infra-red Spectra, Gas Chromatography-Mass Spectrometry. The phenol, 4-(1-methylethyl)-phenol, 4,4-(1-methylethylidene) bis-phenol were found as the main compounds in liquid product, and the mechanism of decomposition was envisaged as the ether and ester bonds cracking, then the E-51/MeHHPA system was degraded gradually.The kinetics analysis of reaction system was carried out through studying glass transition temperature of different residue. The decomposition activation energy of E-51/MeHHPA is 123.50kJ/mol.Besides, model compound was synthesised to simulate the structure of epoxy resin, and then decomposed to reveal and study decomposition mechanism of epoxy resin.
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