A Novel Process to Prepare Ammonium Polyphosphate with Crystalline Form II and its Comparison with Melamine Polyphosphate

Abstract

P 4 O 10 is highly deliquescent and reactive; techniques using non-P 4 O 10 process are not only required for environmental protection, but also for consideration of safety and cost in industrial-scale production. A non-P 4 O 10 process to prepare ammonium polyphosphate with crystalline form II (APP-II) was proposed by heating the mixture of diammonium hydrogen phosphate (DAP) and melamine under wet ammonia. Its water solubility, FT-IR, XRD, and 31 P NMR spectra were compared with those of commercial APP-II and melamine polyphosphate (MPoly), and interesting results were obtained. Thermogravometric analysis (TGA) showed the synthesized APP-II had better thermal stability than commercial APP-II. The reaction mechanism and molecular structure for the subject compound were investigated and discussed in detail.

Enhanced mechanical and flame‐resistant properties of polypropylene nanocomposites with reduced graphene oxide‐functionalized ammonium polyphosphate and pentaerythritol

“…23,24 In addition, the peaks at 1164 (P O stretching vibration), 1080 (P O symmetrical stretching vibration), and 880 cm −1 (P O asymmetric stretching vibration) are attributed to the typical featured bands of polyphosphate chains. [24][25][26] For the FTIR spectrum of GO-APP, the peak at 1232 cm −1 belonging to C OH group disappears completely, whereas a new peak appears at 1022 cm −1 and is related to P O C band. 23,27 Meanwhile, some characteristic peaks appearing in both APP (like N H + , P O, P O groups) and GO (like C O group) curves are also observed as expected.…”

Synergistic effect of graphitic carbon nitride and ammonium polyphosphate for enhanced thermal and flame retardant properties of polystyrene

“…1b. The assignments of APP can be detected at 3400À3030 cm À1 (the asymmetric stretching vibration of NH 4 þ ), 1420 cm À1 (the bending vibration of NH þ ), 800 cm À1 (the vibration absorption), 1350À1100 cm À1 (stretching vibration of P]O), and 1100e850 cm À1 (the stretching vibration of PeOeP) [36,37]. For g-C 3 N 4 , the broad bands at 3000À3500 cm À1 are contributed by NeH stretching vibration and hydrogen bonding interactions; the bands at 1800e1000 cm À1 corresponding to stretching vibration of connected units such as CeN(ÀC)eC or CeNHeC; the absorption band at approximately 810 cm À1 assigned to vibration of the triazine ring [38].…”

“…3b. The first-step decomposition occurs in the range of 250e450 C, resulting from the decomposition of thermally unstable groups such as the terminal chain groups [ÀOP(O)(ONH 4 ) 2 ] and midchain groups [ÀOP(O)(ONH 4 )À], and the elimination of NH 3 and H 2 O during the thermal decomposition of polyphosphate, while the second-step decomposition is initiated by the release of phosphoric acid, polyphosphoric acid, and metaphosphoric acid beyond 450 C [36,39]. The g-C 3 N 4 only shows one-step decomposition process in the whole temperature range.…”

Fire retardant synergism of hydroquinone bis(diphenyl phosphate) and novolac phenol in acrylonitrile–butadiene–styrene copolymer

“…This complex decomposition behavior is believed to be ascribed to the further degradation that polyphosphoric acid undergoes at the same temperature. The polyphosphoric acid is formed in first stage with the elimination of H 2 O [19]. There are about 7.67% of residues left at 800°C.…”