Countermeasures for Agglomeration of Piperazine Pyrophosphate Powder and its Application in Polypropylene.

Piperazine pyrophosphate (PAPP), as a good intumescent flame retardant, is widely used in polyolefin flame retardancy. However, its tendency to agglomerate greatly limits its application in materials. The application of unevenly dispersed PAPP in polypropylene can cause agglomeration, which not only results in white spots in polypropylene products, but also leads to a decrease in flame retardancy. The article combined the analysis of the causes of agglomeration of PAPP and added commonly used dispersants to improve its agglomeration phenomenon. Among them, dispersants included microscale silicides, large-sized silicides, zinc stearate, magnesium stearate, silicone oil, aminosilane, silicone, etc. Firstly, micro-sized silicides, silicones, and silicone oil were screened through heap pressure experiments to have a good effect on improving agglomeration. Furthermore, the influence of dispersants on polypropylene materials was characterized through methods such as thermogravimetric analysis, particle size testing, limited oxygen index testing, UL-94 testing, mechanical properties testing, and melt index testing. The results showed that silicone, silicone oil, and micro sized silicides had a significant improvement effect on the agglomeration of PAPP. Applied in polypropylene, micro sized silicides had the least impact on flame retardant polypropylene and the lowest degree of physical property degradation. Therefore, micro sized silicides were selected as the best additives for improving PAPP. [ABSTRACT FROM AUTHOR]