Role of Poly(vinyl alcohol) in the Crystal Growth of Ammonium Perchlorate

One of the key aspects in the development of new inorganic materials is the synthesis of particles with specific sizes and morphologies. Nowadays, water-soluble polymers as crystal-growth modifiers are gaining more importance in the field of morphogenesis of inorganic crystals. Ammonium perchlorate (AP) is an extensively used solid propellant oxidizer. Oxidizer particles with a particular morphology are a challenging requirement in the propellant field. In the present study, AP with different morphologies was synthesized by the polymer-assisted crystal-habit modification route. Poly(vinyl alcohol) and AP salt solutions were prepared and mixed in different proportions. Samples were drawn from the mixture, dried on glass slides, and analyzed by scanning electron microscopy and powder X-ray diffraction (PXRD). AP crystals with a rectangular prism and a rectangular wedge shape were obtained, and the reasons for their shapes are discussed. The PXRD patterns showed that the phase of AP obtained is the same as the one obtained from its saturated solutions.