Abstract:Lead tannate (Ta-Pb) is usually used as a high-efficiency combustion catalyst for double-base propellants, but its catalytic efficiency is greatly affected by various factors such as chemical compositions and structure. Therefore, the catalytic performance of Ta-Pb is usually not predictable which limits its widely practical applications. In order to solve the above problems, the effects of Ta-Pb samples prepared by both lead oxide and lead acetate methods on the burning rate and pressure exponent of double-base propellants have been investigated. Furthermore, the catalytic combustion properties of Ta-Pb prepared under different conditions, such as different Pb2+ contents and pH values, were studied systematically. The results show that the catalytic performance of Ta-Pb prepared by using lead oxide as the starting material is better than the one prepared by using lead acetate. The burning rate of the double-base propellants increases first and then decreases with the increase of the Pb2+ content in Ta-Pb. When the molar ratio of tannic acid to lead oxide is 1∶5 (Pb2+ content is 31.95%), the as-prepared Ta-Pb has the best catalytic combustion performance, and the burning rate of propellants can reach 32.79 mm·s-1 (at 16 MPa). The Ta-Pb sample obtained by adjusting the pH of the reaction system to neutrality has a significant effect on the combustion performance of the propellants. The optimumized conditions for the preparation of Ta-Pb is as follows: the preparation method is the lead oxide method, the molar ratio of tannic acid to lead oxide is 1∶5, and the pH is neutral. The Ta-Pb prepared under these conditions can increase the burning rate of the double-base propellants to 33.13 mm·s-1 (16 MPa) and make the average pressure exponent less than 0.4 (12-16 MPa).