Investigation Of Ammonium Polyphoste's Synthetic Technology

Ammonium polyphosphate (APP) have been paid much attention because of its excellent characterization on flame retardant. It is unavoidable to synthesize high Degree of Polymerization and pure type Ⅱ-APP, which is the key that makes application of APP to spread further. Some external nations have realized industrialization on producing type Ⅱ-APP. Comparatively the products of domestic enterprises are not ideal on quality, which have greatly influenced APP's beneficial result on society and economy in our country. Some of reasons that bring the situation are the lagging technology of synthesize, the shortcoming on basic investigation, etc. The item took aim at deeply investigating the synthetic technology, finding out the hindering reasons on making ideal APP, further improving quality of Ⅰ-APP. So the item possesses academic and economic value. The study deeply investigated the synthetic technology that used Urea Phosphate as raw materials. Adopted the line of experiments as follow: simulating ambience →exploring temperature →discussing the other factors →seeking optimum technology. Constructed two different polyplants: machinery stirring polyplant and gas stirring polyplant; Compared three different methods of polymerization: machinery stirring, gas stirring and gas cylinder; Explored the pressure of NH3, CO2, H2O and ambience's ingredients; Explored the rate of rising temperature, the rate of lowering temperature, the transform temperature and time of crystal shape; Discussed PH and solvent; Got optimum seeking technology and improved the quality of Ⅰ-APP. Some experiment's results could be showed as follow: Total pressure was 1.512atm, and the pressure of NH3, CO2, H2O were 0.8atm(52.9%), 0.4atm(26.5%), 0.312atm(20.6%) respectively; Got Ⅰ-APP with 50 average Degree of Polymerization, and broke through the limitation that documents had reported on using phosphoric Acid and urea as materials; Got the technical conditions that Ⅰ-APP partly converted into Ⅱ-APP(rising temperature at 240℃, the time of preservation 6h, the pressure of NH3 0.8atm, the pressure of H2O 0.312atm); Suggested two factors retarding the conversion of Ⅰ-APP(uneven reaction in low temperature phase and long time phase transformation in high temperature); Realized the conversion that Ⅰ-APP was made by Heat-phosphoric Acid and Urea without great change on Degree of Polymerization.