20208-95-1Relevant articles and documents
Tris(2,4,6-triamino-1,3,5-triazin-1-ium) Dihydrogenphosphate Monohydrogenphosphate Tetrahydrate
Hausner, Josef,Butterhof, Christian,Martin, Thomas,Milius, Wolfgang,Breu, Josef
, p. 2871 - 2875 (2014)
When "recrystallizing" the commercial flame retardant melaminium orthophosphate, surprisingly a hydrate with a diverging stoichiometry of melaminium (M) and phosphate (P) was obtained (M3P2 ·4H2O). The structure of M3P2 ·4H2O was solved by single-crystal X-ray diffraction analysis. The arrangement of positive melaminium and negative phosphate layers found in the crystal structure allows for both electrostatic attraction and hydrogen bonding networks. The melaminium layers are comprised of hydrogen-bonded ribbons of melaminium, which in turn are connected by π-π interactions into layers. The negatively charged phosphate layers are comprised of hydrogen bonded dihydrogenphosphate dimers and hydrogenphosphate dimers, which in turn are interconnected by direct and water-mediated hydrogen bonding into layers.
Thermal degradation characteristic and flame retardancy of polylactide-based nanobiocomposites
Malkappa, Kuruma,Bandyopadhyay, Jayita,Ray, Suprakas Sinha
, (2018)
Polylactide (PLA) is one of the most widely used organic bio-degradable polymers. However, it has poor flame retardancy characteristics. To address this disadvantage, we performed melt-blending of PLA with intumescent flame retardants (IFRs; melamine phosphate and pentaerythritol) in the presence of organically modified montmorillonite (OMMT), which resulted in nanobiocomposites with excellent intumescent char formation and improved flame retardant characteristics. Triphenyl benzyl phosphonium (OMMT-1)-and tributyl hexadecyl phosphonium (OMMT-2)-modified MMTs were used in this study. Thermogravimetric analysis in combination with Fourier transform infrared spectroscopy showed that these nanocomposites release a smaller amount of toxic gases during thermal degradation than unmodified PLA. Melt-rheological behaviors supported the conclusions drawn from the cone calorimeter data and char structure of the various nanobiocomposites. Moreover, the characteristic of the surfactant used for the modification of MMT played a crucial role in controlling the fire properties of the composites. For example, the nanocomposite containing 5 wt.% OMMT-1 showed significantly improved fire properties with a 47% and 68% decrease in peak heat and total heat release rates, respectively, as compared with those of unmodified PLA. In summary, melt-blending of PLA, IFR, and OMMT has potential in the development of high-performance PLA-based sustainable materials.
Melamine-based functionalized graphene oxide and zirconium phosphate for high performance removal of mercury and lead ions from water
Awad, Fathi S.,Bakry, Ayyob M.,Bobb, Julian A.,El-Shall, M. Samy,Ibrahim, Amr A.
, p. 37883 - 37897 (2020)
Heavy metal ions are highly toxic and widely spread as environmental pollutants. This work reports the development of two novel chelating adsorbents, based on the chemical modifications of graphene oxide and zirconium phosphate by functionalization with melamine-based chelating ligands for the effective and selective extraction of Hg(ii) and Pb(ii) from contaminated water sources. The first adsorbent melamine, thiourea-partially reduced graphene oxide (MT-PRGO) combines the heavier donor atom sulfur with the amine and triazine nitrogen's functional groups attached to the partially reduced GO nanosheets to effectively capture Hg(ii) ions from water. The MT-PRGO adsorbent shows high efficiency for the extraction of Hg(ii) with a capacity of 651 mg g-1 and very fast kinetics resulting in a 100% removal of Hg(ii) from 500 ppb and 50 ppm concentrations in 15 second and 30 min, respectively. The second adsorbent, melamine zirconium phosphate (M-ZrP), is designed to combine the amine and triazine nitrogen's functional groups of melamine with the hydroxyl active sites of zirconium phosphate to effectively capture Pb(ii) ions from water. The M-ZrP adsorbent shows exceptionally high adsorption affinity for Pb(ii) with a capacity of 681 mg g-1 and 1000 mg g-1 using an adsorbent dose of 1 g L-1 and 2 g L-1, respectively. The high adsorption capacity is also coupled with fast kinetics where the equilibrium time required for the 100% removal of Pb(ii) from 1 ppm, 100 ppm and 1000 ppm concentrations is 40 seconds, 5 min and 30 min, respectively using an adsorbent dose of 1 g L-1. In a mixture of six heavy metal ions at a concentration of 10 ppm, the removal efficiency is 100% for Pb(ii), 99% for Hg(ii), Cd(ii) and Zn(ii), 94% for Cu(ii), and 90% for Ni(ii) while at a higher concentration of 250 ppm the removal efficiency for Pb(ii) is 95% compared to 23% for Hg(ii) and less than 10% for the other ions. Because of the fast adsorption kinetics, high removal capacity, excellent regeneration, stability and reusability, the MT-PRGO and M-ZrP are proposed as top performing remediation adsorbents for the solid phase extraction of Hg(ii) and Pb(ii), respectively from contaminated water. This journal is
PROCESS FOR RECOVERING PHOSPHORIC ACID FROM SOLID PHOSPHORUS SOURCES
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Page/Page column 13, (2020/09/08)
The invention pertains to a process for preparing phosphoric acid from a solid phosphorus-containing material, comprising the steps of: - reacting a solid phosphorus-containing material with strong acid in an amount of 1.0-15 mole acid, calculated as protons, per mole of phosphorus (calculated as P) in the solid phosphorus-containing material in a monophasic reaction medium comprising an organic solvent, to form a solution of phosphoric acid in organic solvent and remaining solid material, - separating the solution of phosphoric acid in organic solvent from the remaining solid material. It has been found that phosphoric acid can be recovered from a solid phosphorus-containing material in high purity and efficiency via a solid-state rearrangement/elution process. The process according to the invention does not require the use of the large amounts of water required by the conventional dissolution/extraction processes known in the art. The solution of phosphoric acid in organic solvent can be used as a starting material for further processes.
Synthesis, characterization and thermal behavior of tetrakis(melamine2+) bis(melamine+) pentakis(monohydrogenphosphate) tetrahydrate
Youcef, Hakima Ait,Chafaa, Salah,Doufnoune, Rachida,Douadi, Tahar
, p. 138 - 143 (2016/07/06)
A new organic-inorganic salt, tetrakis (2,4,6-Triamino-1,3,5-Triazin-1,3-diium) bis (2,4,6-Triamino-1,3,5-Triazin-1-ium) pentakis (monohydrogenphosphate) tetrahydrate, 4C3H8N6+2. 2C3H7N6+. 5HPO42-. 4H2O was synthesized through the reaction of melamine and phosphoric acid in an acidic medium HCl/H2O. It was then characterized by X-ray diffraction. The title compound crystallizes in monoclinic system with non-centrosymetric space group P 21 with lattice parameters a = 11.3008 ?, b = 20.9798 ?, c = 12.2679 ?, α = 90°, β = 117.236°, γ = 90°, Z = 2 and V = 2586.10 (?)3. The UV-vis absorption spectrum UV-vis showed that the crystal has a good optical transmittance in the entire visible region with a lower cut off wavelength of 290 nm. The vibrational frequencies of various functional groups present in the crystal were identified by FT-IR analysis. The chemical structure of the compound was also confirmed by 1H, 13C and 31P NMR spectroscopy. TGA-DTA analysis revealed that the materials have a good thermal stability without any melting.
Method for preparing amino phosphate compounds
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Page/Page column 2, (2008/06/13)
The present invention relates to a method for preparing amino phosphate flame retardants. Melamine and phosphoric acid substances are used as a starting material, AND then the starting material reacts in the absence of solvents at a temperature ranging from 40 to 200° C. to obtain powdery amino phosphate compounds used as flame retardants. Since the reaction free of solvents is carried out under a condition of lower temperature, the powdery amino phosphate compounds can be obtained without drying steps. Therefore, not only the contaminations caused by solvent volatilization can be avoided, but also the process of preparing the product is simplified and the cost of the product is reduced.
