Optimization of Epoxy Resin Crosslinking Network Structures and Control of Electron Transport Behavior Using Chloride Ions

The presence of chloride ions as impurities significantly affects the physicochemical and insulation properties of epoxy resins. Here, the chloride ion content (60 ppm, 600 ppm, and 2000 ppm) in epoxy composite samples was varied to explore its influence on the structure of epoxy resin crosslinking networks and electron transport behavior. An evaluation of the mechanical properties of the samples showed that, at a chloride ion content of 2000 ppm, the tensile and bending strength of the sample were 26.98% and 16.49% , respectively, lower than that of the sample with a chloride ion content of 60 ppm. Furthermore, an increase in the chloride ion content reduced the crosslinking density of the sample. The crosslinking density of the 2000-ppm sample was 41.96% lower than that of the 60-ppm sample. The energy band and excited state of the three samples were also simulated based on density functional theory (DFT). The DFT calculations show that a reduction in the chloride ion content is beneficial for the optimization of the electron transport in the crosslinked network. This paper outlines a method for optimizing the crosslinking network structure of chloride ion epoxy composites and regulating the electron transport behavior.