Study On Hyperbranched Amine Cured Epoxy Resin System

In the high strength and high toughness of large composite structure parts of moldingprocess, the formulated epoxy resin matrix be demanded with low viscosity, adjustablereactivity, high flexibility and excellent mechanical toughness. The traditional toughenedepoxy resin system will improve viscosity, reduce the flow of resin system, which wasproved not to the molding composite material;at the same time, the method of reduce thetechnology system of epoxy resin viscosity by adding solvent system or low boiling pointhigh mobility curing agent also caused environment pollution, which was not suitable forlarge composite structure parts. However, hyperbranched polymer amine as curing agent ofepoxy resin can reduced the viscosity of resin system, speeded up the curing rate andimproved the mechanical toughness of the resin system, which maybe meet to therequirement of molding, high strength and high toughness of large composite.Used hyperbranched polyethylenimine and isophorone compound amine as curingagent, on the one hand, we studied curing behavior and curing kinetics of epoxy resinsystem by DSC research of method; on the other hand, the variation law of mechanicalpropertiesand the glass transition of different polyethylene imine content on the curing ofepoxy resins also be developed; in addition, the study of fracture morphology of the epoxyresin by SEM were researched.The results show that: the introduction of hyperbranched polyethylenimine reduced theviscosity of the epoxy resin system and the curing reactions of IPDA epoxy resin curingsystem activation energy, improved the construction process adaptability, which arrived tothe purpose of lowing the initial reaction temperature and speeding up the curing rate. Withthe increasing the content of hyperbranched polyethyleneimine, the mechanical strength ofthe epoxy resin gradually decreased, while the mechanical toughness and presents the trendof first increased then decreased. And the epoxy resin system showed two glass transitiontemperatures and microphase separation phenomenon, epoxy resin tensile fracture in SEMphotographs becomed more rough, crack branching increased, reflected better than singleIPDA curable resist shock. When the content of polyethyleneimine SP-012arrived to10mol%, cured epoxy resin had the best mechanical properties, the tensile strength andflexural strength increased by10%, the unnotched impact strength increased by150%.