The invention provides a determination method for the reaction activity order of active
hydrogen-containing components and a curing agent in a
propellant, wherein the method is applied to the field of nuclear
magnetic analysis of
spaceflight fuels. The method comprises the following steps: determination of a detection object; preparation of detection samples; selection of detection conditions; implementation of sample detection; and
processing of detection data. According to the invention, a mixed
uniform system of active
hydrogen-containing components and
toluene diisocyanate (TDI) in the
propellant is taken as the detection object. To prepare the samples, groups are proportioned according to concentrations, grouped and then uniformly mixed; and a proper amount of the samples are selected and placed in a chromatographic
bottle. A low-field
nuclear magnetic resonance spectrometer is employed, and the detection conditions are selected. The changing curve of spin-
spin relaxation time T2 with reaction time is detected, each
vertical coordinate of the curve is normalized, and the reaction activity order of each component and TDI is acquired according to the speed of slope changes before the curve tends to be flat. The determination method provided by the invention has the advantages of simple operation, safety in experiments, reduction in cost, reliable experimental data, optimized detection conditions and simplified detection process.