Study On Modified Liquid DDM Medium Temperature Curing System Of Heat Resisting For Epoxy Resin

At present, it is a hot research that using of lower curing temperature has obtained higher heat resistance of epoxy resin system. The main way of research is to select appropriate curing agent and promoting agent, through modified and built methods reduce the curing temperature at the same time ensure that the resin possesses higher heat resistance temperature and excellent mechanical properties, which makes the modified epoxy resin curing system as a high-performance matrix of composite material used.Through a lot of fumbled experiment, this research selected liquid 4,4'-diamino diphenyl methane (liquid DDM) and fatty amine A binary as the staring material, used the modified method of thiourea-polyamine condensation reaction, utilized the two schemes of orthogonal experiment method and single factor method and modified liquid DDM. Some technological parameters of the synthesis had been inspected, the factors, such as ratio of material, reaction temperature and reaction time and so on, influencing on the product viscosity, heat resisting and impact ductility. The outcomes of two experiment schemes had been compared, sequentially, suitable conditions of the synthesis were determined.The best dosage of curing agent had been confirmed with Gelprof518 resin reaction behavior analyzer. The curing system of epoxy resin was studied by DSC, and the curing characteristics of liquid DDM(before and after the modification) / epoxy were analyzed and compared, the curing reaction kinetic parameters and the best curing process conditions were researched and determined. The resin condensate was impacted test and the impact of cross-section was analyzed by scanning electron microscopy (SEM), and the mechanical properties of the resin condensate were studied, at the same time, using the dynamic mechanical thermal analyzer(DMA) and thermal deformation temperature of Vicat softening point(HDT) researched the heat resisting property of resin condensate, Based on this study the content of binary fatty amine A influencedon the mechanical properties and thermal stability property were studied.In a word, the characterization of the product, the resin curing system and curing condensate of resin were detected by a variety of methods of performance testing, the results showed that the modified medium temperature curing system of heat resisting for epoxy resin matched the researchgoal, that is using of lower curing temperature has obtained higher heat resistance of epoxy resin system, moreover, the resin condensate possessed optimum mechanical properties.