Determination of acid value of CL-20 by titration method

To establish feasible method to determine the acid value of hexanitrohexaazaisowurtane (CL-20), through comparing potentiometric titration method with indicator titration method and screening out the best solvent and indicator, the best system to determine the acid value was obtained. The results show that the optimum potentiometric titration system is sodium hydroxide/water solution as titrant and mixed solution of 250 mL slightly acidic acetone and 50 mL water as solvent. The optimum indicator titration system is the above titrant and solvent, and the neutral red-methylene blue as the indicator. The standard deviation of above two methods is less than 0.00030311% and the minimum is 0.00001%. The relative standard deviation of above two methods is less than 0.99949%, and the minimum is 0.19458%. The substitution of potassium hydroxide/ethanol for the sodium hydroxide/water in the above titrant can also meet the operating requirement.