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Preparation of aluminum electrolytic capacitors work electrolyte additives is one of the key technologies to improve the performance of the work electrolyte. Carboxylic acid esters of polyethylene glycol is a multifunctional macromolecule polymer, has a wide range of applications in the chemical industry. The systematic study optimal synthesis process of polyethylene glycol 400 succinate (PEGS), testing and structural characterization of the physical and chemical properties of synthetic PEGS and PEGS work electrolyte performance, as well as PEGS in aluminum electrolytic capacitors. The main content of this article is as follows. Direct esterification method using a solvent, and no catalyst, under conditions of negative pressure to the polyethylene glycol 400 and the succinic anhydride was synthesized PEGS. The reaction temperature, reaction time, and reaction of the negative pressure on the esterification reaction, the esterification rate of the reaction, the acid number and average molecular weight of the product to determine the reaction of the acid to alcohol molar ratio. The results show that: the optimum conditions of synthesis PEGS reaction temperature 160 ℃, reaction time 4 h, the reaction negative pressure 15KPa acid molar ratio of 3:2. Under this condition, the esterification rate reached 98.81%. NDJ-1 rotational viscosity meter KF-II-type trace moisture analyzer, HG / T 2708-1995, FT-IR and TG methods and means testing and structural characterization of the physical and chemical properties of the synthesized product PEGS. The results showed that: PEGS for synthesis of both terminals of the carboxyl ester compound, a viscosity of 120 mPa · s, a water content of 0.83%, an acid value of 103.5mg KOH / g, a better thermal stability, PEGS in temperature to 185 ℃, weight loss is only 1.4%, until the temperature rose to about 430 ℃ completely weightless degradation applies to the working temperature is below 150 ° C. The aluminum electrolytic capacitor electrolyte. Synthetic PEGS added to the aluminum electrolytic capacitor electrolyte, examines the impact of the addition and the pH value of the PEGS spark voltage aluminum electrolytic capacitor electrolyte conductivity. The results show that: PEGS can improve the working electrolyte spark voltage, while effectively suppressed conductivity reduction, add PEGS mass fraction of 3%, the spark voltage working electrolyte elevated 45V conductivity only reduce 100 × 10 -6 S / cm or so, PEGS do additives optimum pH value of 6.0. Working electrolyte containing PEGS applied to the aluminum electrolytic capacitor, the life test, the electrical capacity of the aluminum electrolytic capacitor, leakage current, and the loss tangent value, life and other performance study. The results showed that: Add PEGS, the aluminum electrolytic capacitor leakage current is small, the loss is small, and the rate of change of the loss and the power capacity is reduced, improving the thermal stability of the aluminum electrolytic capacitor, extending the life of the electrolytic capacitor, at 35 ° C room temperature, aluminum electrolytic capacitor life expectancy of up to 140 years.
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