Preparation And Safety Evaluation Of Environmental Friendly Aliphatic Amine Epoxy Curing Agent

Due to its excellent physical and adhesive properties,high mechanical strength and high temperature resistance,epoxy resins have been widely used in insulation materials,coatings,and adhesives for more than ten years.However,most epoxy resins are only soluble in organic solvents.With the continuous progress and development of human society,people's awareness of environmental protection has been gradually improved.Systems that contain no or few volatile organic compounds(and harmful air pollutants)have become The research direction of new materials,water-based epoxy systems with water as the solvent or dispersion medium is getting more and more attention.In this study,the triethylenetetramine used in the market is the subject of research.The experimental subject is a two-step chain extension reaction.First,triethylenetetramine reacts with monoepoxide AGE to introduce a hydrophilic glycidyl ether segment.Reducing its activity and making it surface active,then reacting with epoxy resin E44,chain extension is performed again,epoxy resin molecular chain segments are introduced,so that it has a matching molecular structure with epoxy resin,and its emulsifying performance is increased.The results show that the curing agent prepared when AGE:E44:TETA=1.2:0.5:1(molar ratio)is used for the best performance.In order to improve the water solubility of the modified curing agent,the pH of the curing agent is balanced by adding glacial acetic acid to the curing agent to increase its water solubility.The results show that when the mass ratio of the modified curing agent to glacial acetic acid is 33:1,the coating effect of the curing agent is not affected and the water solubility is optimal.The results of the reaction temperature and reaction time during the modification reaction show that the optimum reaction temperature of the modified curing agent is 50°C.and the reaction time is 3 h.The obtained film adhesion is 0,the hardness is 3H,and the salt spray is Level 9.The prepared water-borne epoxy curing agent and the self-made emulsion were mixed and coated,and the curing kinetics of the epoxy resin was analyzed by differential scanning calorimetry(DSC method)to calculate the curing reaction temperature of the epoxy resin.Biological toxicity test to test the change of toxicity before and after the curing agent is modified.