Modified aliphatic amine epoxy resin curing agent, preparation method thereof and cured epoxy resin

The invention discloses a modified aliphatic amine epoxy resin curing agent, a preparation method thereof and an epoxy resin cured product, the curing agent is weak in volatility and low in toxicity, the curing agent contains hydroxyl groups at two ends, the crosslinking density of a final epoxy resin product can be improved, and caprolactone in a molecular chain can improve impact toughness and low-temperature performance of the cured product. The preparation method is simple, convenient and easy to operate, the epoxy resin castable prepared on the basis of the curing agent has high impact strength and low temperature resistance on the premise that mechanical properties, electrical insulation properties and heat resistance are not affected, meanwhile, many caprolactone oligomers are used in the raw materials, and the curing agent is environmentally friendly. The problem that the caprolactone oligomer is difficult to treat is also solved, the preparation method is simple and easy to operate, and the productio