Hello,

I want to help U but this but this topic is beyond my scope :(

Regards

Dear César,

The main reason for the larger use of ammonium polyphosphate (APP) II could be linked to its higher thermal stability (the beginning of thermal decomposition at about 300 °C, much higher than of AAPP I, about 150 °C), and due to its lower water sensitivity. Therefore, I believe that APP II is among the best options as FR for many polymers.

However, there are few papers/applications dealing with the use of APP I, e.g. The Effect of Soluble Ammonium Polyphosphate on the Properties of Water Blown Semirigid Polyurethane Foams https://doi.org/10.1155/2017/5282869, consequently, your assumption regarding the limited number of papers appears correct. Regarding your question, APP I can be used in different polymer systems, but the key condition is to work at lower temperature than the onset of its thermal degradation (150 °C). That there are not some constraints, APP II has additional features...

Good luck in your R&D projects/work and best regards,

Marius

Thank you Marius,

Your coment confirm my suspect but my guess is that the lack of use of APP I is more related with the acidity affecting the kinetics of the foaming process rather than the thermal stability.

Let´s see if someone has first hand information.

Regards,

César