硬脂酸溶胶—凝胶法制备超细LaCoO_3及对硝胺改性双基推进剂燃烧性能的影响研究

The Preparation of Ultrafine Powder LaCoO_3 via Stearic Acid Sol-Gel Method and the Effect of LaCoO_3 on Combustion Characteristics of Nitramine Modified Double Base Propellant

以硬脂酸为络合剂，采用溶胶-凝胶法制备了钙钛矿型超细复合氧化物LaCoO3．运用差热-热重（DTA-TG）、傅立叶变换红外（FT-IR）光谱、X射线衍射（XRD）、透射电镜（TEM）对生成LaCoO3的超细粉末进行了表征。比较了湿凝胶的两种干燥方法对产品团聚程度的影响。初步测试了超细LaCoO3粉体对硝胺改性双基推进剂的燃速和压力指数的影响。结果表明：干燥湿凝胶时加入干燥剂无水硫酸钠脱水比真空干燥所得粉体具有团聚程度轻，粒径小的特点；将所得的超细粉体LaCoO3按1．7％（质量百分比）比例加入硝胺改性双基推进剂中，在3～18MPa范围内，显示了提高燃速，降低压强指数的作用，且在14～16MPa压强范围内产生了平台燃烧效应。

Ultrafine perovskite-type complex oxide LaCoO3 was prepared with a sol-gel method using stearic acid as complexing agent. The product was characterized by differential thermal analyzer and thermal gravimetry（DTA-TG）, Fourier transform-infrared（FT- IR） spectrum, X-ray diffraction（XRD） and transmission electron microscope （TEM）. The effect of the two dry methods of wet gel on the product group degree was compared. The effect of ultrafine powder LaCoO3 on the buring rate and the pressure exponent of nitramine modified double base propellant was primarily tested. Experimental resuits show that well-dispersed perovskite-type LaCoO3 ultrafine powder is able to be obtained easily when wet gel is dried with anhydrous sodium sulfate Na2SO4 instead of evaporating slowly; when 1.7 % （w） perovskite-type LaCoO3 is added in the propellant, the burning rate of the propellant is enhanced, the pressure exponent is decreased in the range of 3-18 MPa, and the platform burning behavior appears in the range of 14-16 MPa.