THERMAL-BEHAVIOR OF AMMONIUM POLYPHOSPHATE INORGANIC COMPOUND MIXTURES .1. TALC

The chemical interaction between ammonium polyphosphate (APP) and talc was studied under dynamic or isothermal heating conditions. The products of interaction were identified by X-ray methods or separated by thin layer chromatography and analysed. It was shown that APP decomposes above 280-degrees-C and starts to interact with talc above 300-degrees-C, giving binary ammonium silicon tetrapolyphosphate and ammonium magnesium polyphosphate or cyclophosphate depending on the initial APP/talc ratio in the mixture. The formation of magnesium cyclotetraphosphate, magnesium ultraphosphate, silicon oxymonophosphate and silicon diphosphate is observed after further heating at 400-800-degrees-C. A glass of magnesium silicon phosphate is formed at 1000-degrees-C. The schemes of chemical reactions occurring at different temperatures are proposed for various APP/talc ratios.