酸碱滴定法测定复合固体推进剂燃烧产物中氯化氢

Determination of hydrogen chloride in combustion products of composite solid propellants by acid-base titration

设计了一套固体推进剂燃烧产物收集装置,建立了酸碱滴定法测定燃烧产物中氯化氢含量方法。在密闭燃烧产物收集装置中,采用Φ36 mm实验发动机试车,加入1 L 1 mol/L氢氧化钠溶液吸收燃烧产物,并用氢氧化钠溶液将气体收集罐内部清洗干净,合并吸收液并准确称取质量。吸收液静置17 h后准确称取上清液约20 g进行测试。以甲基橙为指示剂,控制滴定终点pH在3.4左右,使Al^(3+)和CO_(2)以进入体系的初始状态存在于终点体系中,消除Al^(3+)和CO_(2)的影响,用0.1 mol/L盐酸标准滴定溶液滴定吸收液中剩余的氢氧化钠,得到推进剂燃烧产物中氯化氢含量。该法测定结果的相对标准偏差小于2%(n=6),测定结果与理论计算值的相对偏差在0~-1.5%之间,燃烧产物收集装置设计合理。

A collection device for solid propellant combustion products was designed,an acid-base titration method for determining the content of hydrogen chloride in combustion products was established.In a closed combustion product collection device,the experimental engine with diameter 36 mm was used for test run,1 L sodium hydroxide solution with the concentration of 1 mol/L was added to absorb combustion products,then cleaned the inside of the gas collection tank with sodium hydroxide solution,merge the absorbing solution and weigh it accurately.The absorption solution was let to stand for 17 hours.About 20 g supernatant was weighed accurately for testing.Methyl orange was used as the indicator,pH of the titration endpoint was controlled about 3.4,so that Al~(3+)and CO_(2) existed in the endpoint system just as their initial state when they entered the system,eliminating the influence of Al~(3+)and CO_2,titrated the amount of sodium hydroxide in the test solution by using 0.1 mol/L hydrochloric acid standard titration solution,obtaining the content of the hydrogen chloride in propellant combustion products.The relative standard deviation of the this method was less than 2%(n=6),and the relative deviation between the measurement results and the theoretical calculation value was between 0 and-1.5%.The design of the combustion product collection device is reasonable.