Brodski Vladimir, Peschar René, Schenk Henk, Brinkmann Andreas, Bloemberg Tom G, van Eck Ernst R H, Kentgens Arno P M
Universiteit van Amsterdam, van't Hoff Institute for Molecular Sciences, Laboratory for Crystallography, Nieuwe Achtergracht 166, 1018WV Amsterdam, The Netherlands.
J Phys Chem B. 2005 Jul 21;109(28):13529-37. doi: 10.1021/jp0512715.
The crystal structure of the environmentally friendly flame retardant melaminium polyphosphate (MPoly) (2,4,6-triamino-1,3,5-triazinium x PO(3))(n)was determined by a direct-space global optimization technique from X-ray powder diffraction data. Solid-state NMR was used to corroborate the proposed hydrogen-bonding model and to determine the average degree of polymerization (n > 100). An analysis of the crystal structure of MPoly reveals aspects of molecular geometry and packing that are characteristic for melamine-containing compounds and polyphosphate salts. A comparison of MPoly with the crystal structures of its precursors melaminium orthophosphate (MP) and melaminium dihydrogenpyrophosphate (MPy) provides insight in the mechanism of the endothermic dehydration processes that takes place in the reaction path MP --> MPy --> MPoly. Solid-state NMR characterization of various samples of the same batch showed inhomogeneities in the MPoly composition. Various quantities of orthophosphates were found, which cannot be assigned to be MP.
通过直接空间全局优化技术，根据X射线粉末衍射数据确定了环境友好型阻燃剂三聚氰胺多磷酸盐（MPoly）（2,4,6 - 三氨基 - 1,3,5 - 三嗪鎓xPO(3)）(n)的晶体结构。采用固态核磁共振技术来证实所提出的氢键模型，并确定平均聚合度（n>100）。对MPoly晶体结构的分析揭示了含三聚氰胺化合物和多磷酸盐的分子几何形状和堆积方面的特征。将MPoly与其前体正磷酸三聚氰胺（MP）和焦磷酸二氢三聚氰胺（MPy）的晶体结构进行比较，有助于深入了解在反应路径MP→MPy→MPoly中发生的吸热脱水过程的机制。同一批次不同样品的固态核磁共振表征显示MPoly组成存在不均匀性。发现了各种数量的正磷酸盐，它们不能归属于MP。
