高效阻燃剂聚磷酸铵的合成工艺研究

以磷酸和尿素为原料合成了高聚合度的聚磷酸铵。通过单因素实验对制备工艺进行了优化，考察了原料配比、升温速率、预聚合温度、固化温度和固化时间等对产品质量的影响，采用核磁共振法（NMR）测定了聚磷酸铵的平均聚合度，并用X射线衍射(XRD )和红外(IR)相结合的方法对产品的晶体结构进行了表征，同时测定了聚磷酸铵的溶解度和总磷含量。结果表明，最佳制备工艺条件为：n（磷酸)∶n（尿素）=1∶1.9，预聚合阶段升温速率为2～3 ℃/min，预聚合温度为130 ℃，固化温度为230 ℃，固化时间为90 min。此条件下合成的聚磷酸铵平均聚合度为114，水中溶解度为0.492 g，总磷质量分数为31.75%，XRD表征结果表明，所得产品为Ⅰ型聚磷酸铵。

Study on synthetic technology of high efficiency flame retardant ammonium polyphosphate

Ammonium polyphosphate(APP)with high polymerization degree was prepared using phosphoric acid and urea as raw materials.Preparation process was optimized by single factor experiments and the effects of mix ratio of raw materials,heating rate,pre-polymerization temperature,curing temperature,and curing time on quality of APP were investigated.Average polymerization degree of the products was measured by means of nuclear magnetic resonance(NMR) and crystal structure of the products was characterized by means of X-ray diffraction(XRD) and infrared(IR).Solubility and total phosphorus content of APP were also measured.Results showed that the optimal conditions were as follows:n(H3PO4)∶n =1∶ 1.9,heating rate of pre-polymerization stage was at 2～3 ℃/min,pre-polymerization temperature was 130 ℃,curing temperature was 230 ℃,and curing time was 90 min.Under the optimal conditions,average polymerization degree of prepared APP was 114,solubility of APP was 0.492 g,and total phosphorus content of APP was 31.75%(mass fraction).XRD result identified the prepared product was APP-I.