Phase equilibria in binary subsystems of urea-biuret-water system

被引：15

作者：

Babkina, T. S. ^{[2
]}

Kuznetsov, A. V. ^{[1
]}

机构：

[1] Moscow MV Lomonosov State Univ, Dept Mat Sci, Moscow 119991, Russia

[2] Moscow MV Lomonosov State Univ, Dept Chem, Moscow 119991, Russia

来源：

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY | 2010年 / 101卷 / 01期

关键词：

Urea; Biuret; Thermal decomposition; Enthalpy of fusion; Phase diagram; DSC; TG; THERMAL-DECOMPOSITION; HEAT-CAPACITIES; SOLUBILITY; DERIVATIVES; ENTHALPIES; PRESSURES; STATE;

D O I：

10.1007/s10973-010-0829-2

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

Joint results of the differential scanning calorimetry (DSC) and thermogravimetry (TG) experiments were the basis for the fusion enthalpy and temperature determination of the biuret (NH2CO)(2)NH (synthesis by-product of the urea fertilizer (NH2)(2)CO). Recommended values are Delta(m) H = (26.1 +/- A 0.5) kJ mol(-1), T (m) = (473.8 +/- A 0.4) K. The DSC method allowed for the phase diagrams of "water-biuret," "water-urea," "urea-biuret" binary systems to be studied; as a result, liquidus and solidus curves were precisely defined. Stoichiometry and decomposition temperature of the biuret hydrate identified, composition of the compound in "urea-biuret" system was suggested.

引用

页码：33 / 40

页数：8

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