METHOD OF DETERMINING CRYSTALLINITY OF DIPHENYLAMINE-BASED COMPOSITIONS Russian patent published in 2015 - IPC C07C211/55 G01J3/30 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of determining crystallinity of binary phlegmatising compositions based on diphenylamine (DPA), which do not contain other imine and amine compounds. The method can be used, for example, to study the nature of distribution of components in a composition, porosity in a diffusion zone and other physical and chemical properties of propellant powder. The method is based on using an infrared spectroscopy method and includes the following: preparing samples in molten form; taking photometric measurements in the 3300-3400 cm^-1 range and calculating crystallinity (X) using the formula: $$Х=\frac{{С}_{Х}}{{С}_{\text{DPA}}}\cdot 100\%,$$ where C_DPA is the ratio of absorption band intensities of a doublet of valence vibrations of NH groups of the initial DPA at υ₁=3380 cm^-1 to υ₂=3350 cm^-1 $${С}_{\text{DPA}}=\frac{J_{NH3380}}{J_{NH3350}}$$ C_X is the ratio of absorption band intensities of a doublet of valence vibrations of NH groups in the investigated mixture at υ₁=3380 cm^-1 to υ₂=3350 cm^-1. It is preferable to use only high-melting compounds (boiling point higher than 100°C) to determine DPA.

EFFECT: method improves accuracy of determining crystallinity and enables to select an optimum composition for phlegmatisation of energy compositions.

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