Preparation And Performance Measurement Of DG4 Corrsion And Scale Inhibitor And Bactericide

The problem of corrosion, scale and microbe-growing is unavoidable when copper is used in high temperature and cycle water concentrated many time for long time. In order to solve this problem, chemistry is always acceded to cycle cooling water in industry. In this paper, different compound-effects are investigated between corrosion inhibitor, scale inhibitor and bactericide. DG4 is exploited, which can inhibit corrosion and scale and kill bacterium.DG1, one of efficient components in DG4, has been studied by former investigators of our group. But some problems still remaine, for example its purity is low and the performance is not enough better using DGl or BTA alone. Firstly, three-step synthesis is replaced by one-step, by optimizing the process of synthesis, the purity of DGl increases by far. In order to enhance the corrosion efficiency of DGl, DG2 is obtained, which is combined DGl with BTA at appropriate proportion. Besides these, a new series highly effective corrosion and scale inhibitor of copper (DG3) is made up of DG2 and the better effective scale inhibitor screening from two commercial products. Choosing the appropriate concentration of bactericide, DG4 is exploited, which is combined DG3 with the appropriate bactericide. DG4 can inhibit corrosion, scale and kill bacterium at the same time.The results show that when the use level of bisphenol A is 1mol, the optimal synthesis condition of DGl is the use level of caustic soda is 4mol, the use level of chloroacetic acid is 3mol, the reaction temperature is 90 ℃ and the reaction time is 2h. In this condition the purity of crude DGl can increase to 95.51%, which is 11.91% higher than that of the product made from the former process. The corrosion test results show that the corrosion efficiency of DG2 is better than that of BTA or DGl, which is formed by BTA and DGl at the ratio of two (2mg/L) and three (3mg/L). In the two commercial scale inhibitors, PBTCA (5mg/L) has better performance, DG3 has perfect inhibit scale efficiency, and DG3 has uniform efficiency with using DG2 alone. With the increasing of PH, the inhibit corrosion efficiency of DG3 is enhanced, and the inhibit scale efficiency is reduced, but the range of reduce is little, in the common PH of cycle cooling water (PH=7.5~8.5), DG3 has perfect inhibit corrosion and scale efficiency. DG4 has perfect efficiency of inhibit corrosion and scale and kill bacterium, which is made up of DG3 and 10mg/L benzalkonium bromide. The electrochemical polarization of tin brass in DG4 is 22982.28ft, the corrosion speed is 0.000319 mm/a(30℃), 0.001248 mm/a (50℃) , 0.002570 mm/a (70℃) , it is lower than 0.0050mm/a (GB). DG4has good inhibit scale efficiency, which can tolerate 238.85 mg/L (30°C) , 139.46 mg/L (50°C ) , 84.64 mg/L (70 T? ) Ca2+ in fresh water. At the same time, DG4 can kill bacterium perfectly, the bactericidal ratio to sulfate-reducing bacteria and iron bacteria is 99.8% and 98.9%.According to the results, it can conclude that DG4 is a new highly effective corrosion and scale inhibitor and bactericide. Besides that, DG4 is more economic and environment-friendly.