复合推进剂凝聚相燃烧产物成分分析方法

In order to obtain accurate and reliable physicochemical properties of condensed phase combustion products (CCPs) of composite propellants, a method of ethylenediamine tetraacetic acid (EDTA) titration based on microwave digestion was proposed to achieve the quantitative analysis of the total components of condensed phase combustion products. Four groups of condensed phase combustion products of propellant were obtained by using self‑developed condensed phase combustion products collection system. The determination accuracy of EDTA titration, inductively coupled high frequency plasma emission spectrometry (ICP), gas volumetric method and potassium dichromate titration were compared and analyzed for the content of active Al. The results show that the EDTA titration method based on microwave digestion can accurately determine the contents of Al, Al₂O₃, AlN, Fe₂O₃ and C in the condensed phase combustion products of composite propellants. Microwave digestion can effectively dissolve the Al₂O₃ shell coating on the surface of active Al. The optimal parameters of microwave digestion is supposed to be V_H3PO4:V_H2SO4:V_HNO3=10:2:1. The temperature was 240 ℃, and the digestion time was 150 min. ICP spectroscopy can also detect all component contents of condensed combustion products, with a precision slightly lower than EDTA titration. The content of active Al in condensed phase combustion products determined by gas volumetric method and potassium dichromate titration was significantly lower than that determined by EDTA titration and ICP spectrometric method. EDTA titration is the most accurate method to determine the content of active Al. Compared with gas volumetric method, potassium dichromate titration method and ICP spectrometric method, the accuracy of EDTA titration is improved by 60%, 40% and 22%, respectively.