Papers by Author: Gou Sheng Liu

Abstract: Ammonium polyphosphate (APP) has six crystalline forms, different crystalline forms can transform from one form to another. In this paper, the effect of crystalline seed on crystalline transformation is investigated, results show that adding crystalline seed APP II at higher temperature is helpful to form APP II. The transformation between form II and form V at different reaction conditions are also investigated, including blowing wet ammonia to the reaction mixture. The results are informative for controllable preparation of APP in industrial production.

Abstract: Ammonium polyphosphate (APP) is an effective intumescent flame retardant, it has different crystalline forms and therefore, different application. By process of diammonium hydrogen phosphate, the intermediate APP-X in between ammonium polyphosphate form II (APP-II) and form V (APP-V) was found and measured. The transformation process from APP-X to APP-II were studied and discussed. The XRD patterns in this process were discussed in detail so that the crystalline transformation process from APP-X and APP-II can be understood.