APPLICATIONS OF THE TITANOUS CHLORIDE-BUFFER METHOD TO THE DETERMINATION OF NITROGUANIDINE

摘要

A method of determining the nitro-?guanidine content of propellants by the titanous-chloride method in the presence of nitrocellulose has been developed. In this method the propellant residue remaining after extraction with carbon tetrachloride or an azeotropic mixture of n-pentane and methylene chloride is dispersed in water. The nitroguanidine is leached out, while the nitrocellulose remains insoluble. The entire mixture is transferred to a volumetric flask and diluted to volume with water. After the insoluble material settles, an aliquot is withdrawn from the supernatant liquid and transferred to a special titration flask containing a measured volume of titanous chloride solution buffered with sodium acetate to a pH of approximately five. After being stirred for three minutes, the solution is titrated with a standard solution of ferric alum, using ammonium thiocyanate as indicator, and the nitroguanidine content of the pro?pellant is then calculated.