Study of methods for improving the water permeability of ballistite compounds

Processability of present-day highly filled ballistite-type compositions on regular equipment is a real-time issue in the production of powders and propellants. This poses a number of difficulties, in the wringing phase in particular. In this context, wringing the powder mass containing a hydrophilic filler, lead-nickel complex of phthalic acid (LNP), as burning modifier was considered. The main factors responsible for low water permeability of the powder mass and the major relationships in the filtration process were examined. An approach was proposed for improving the water permeability of the composition mass through the use of polyacrylamide (PAM) type water-soluble flocculants and hydrophobization of LNP with organosilicon compounds from among aryl-substituted orthosilicic esters. The effect exerted by PAM of different grades with methyltriethoxysilane as hydrophobizer on the water permeability of the composition containing 5–10% LNP was examined. The method based on using PAM was shown to be the most preferable, with Praestol 650 BC cation-active polyacrylamide being the most efficient flocculant. An indisputable advantages of the approach proposed is that is allows improving the water permeability of a powder mass through using a small amount of the flocculant without affecting the main properties of the composition.