Preparation And Characterization Of Ammonium Polyphosphate By Non P₂O₅ Process

In recent years, halogen-free flame-retardants have drawn more and more attentions compared to those traditional halogen flame retardants due to awareness of environmental protection. Ammonium polyphosphate is a halogen-free flame retardant, it contains both phosphorus and nitrogen, and there are synergistic effects in this halogen free flame retardant.APP is mainly produced by P2O5-DAP or P2O5-DAP-Urea process whose raw materials are P2O5. As is well known, P2O5 is chemically active, it can steadily acts with water or organic materials and releases a lot of heat, thus it is dangerous for the operaters and for industrial control. Furthermore, P2O5 was made from yellow phosphorus, because the process to prepare yellow phosphorus consumes much energy, the use of yellow phosphorus is not energy-saving and ejection-decreasing, it is of significance to develop a new way to produce APP by non-P2O5 process.In this paper, APP was synthesized by using DAP and different condense agents such as melamine(MEL), urea and melamine phosphate (MPP). The synthesis conditions were investigated, such as the ratio of raw materials, reaction time and solidification time. The optimum conditions were obtained with certain mole rate, temperature and under suitable ammonia atmosphere.The synthesized products by different processes (DAP-MEL, DAP-Urea, DAP-MPP) was characterized by XRD and FTIR, their properties such as water solubility and thermal stability were tested according to Chinese Industry Standard for APP (HG/T 2770-2008). On this basis, measurement of water solubility were discussed in detail.The way to produce APP proposed in this paper was two-step, which can alleviate the corrosion caused by the phosphates at high temperature. It it possible to be used in larger scale-up production of APP.