| Imidazole curing agents have high activity and low toxicity,and are widely used as high-performance room temperature curing agents..However,the poor compatibility of most imidazole curing agents with epoxy resins and the short pot life of the resin system have greatly limited its application in the field of liquid molding composites.In this thesis,2-ethyl-4-methylimidazole(2E4MI)was modified with two functionalized monofunctional epoxy reactive diluents,n-butyl glycidyl ether(BGE)and octyl glycidyl ether(EGE).The relationship between the structure of the modified 2E4MI and the curing behavior was explored,the main work is divided into the following aspects:1、A high-purity latent imidazole curing agent was prepared in one step using a solvent-free method.The effects of the ratio of the experimental raw materials,the reaction time,and the modifier droplet acceleration rate during the process of BGE and EGE modified 2E4MI were investigated,and the optimum modification process was determined.2、In this paper,the structures of BGE-MI and EGE-MI were characterized by 1H NMR,FTIR,elemental content analysis and time-of-flight mass spectrometry,determines monofunctional epoxy reactive diluent modified imidazole reaction mechanism.3、The potential and curing behavior of BGE-MI and EGE-MI were systematically studied,and obtained pot life,gel time,optimum curing agent usage.The activation energy and curing behavior of 2E4MI/AFG90,BGE-MI/AFG90,and EGE-MI/AFG90 epoxy resin systems were systematically investigated by non-isothermal DSC testing methods.The study found that activation energy EGE-MI/AFG90>BGE-MI/AFG90>2E4MI/AFG90,proved that BGE-MI and EGE-MI reaction activity decreased,and the latency was improved.4、Through mechanical testing,DMTA,rheological tests,cure shrinkage,Vicat softening point,SEM and other methods proved that BGE-MI/AFG90,EGE-MI/AFG90 resin system has excellent mechanical properties,high thermal stability,low Curing shrinkage and has good practicality. |
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