A new method of preparing anhydrous magnesium carbonate (MgCO3) under high pressure and its thermal property
A new method of preparing anhydrous magnesium carbonate (MgCO3) under high pressure and its thermal property
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DOI：
10.1016/j.jallcom.2017.01.258
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发表时间：
2017-04
影响因子：
6.2
通讯作者：
Liang Wen;Yinggen Yuan;L. Wang;L. Chen;Heping Li
中科院分区：
文献类型：
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作者：
Liang Wen;Yinggen Yuan;L. Wang;L. Chen;Heping Li
以三水合碳酸镁（MgCO3·3H2O）为原料，首次采用高压脱水法制备了无水碳酸镁（MgCO3）。采用粉末x射线衍射（XRD）和拉曼光谱对合成样品的性质进行了表征。在各种条件下进行高压合成，确定最佳条件为3gpa、800℃、1h，合理解释了高压合成mgco3的原理。扫描电镜（SEM）观察到的微颗粒尺寸超过100 μm。作为一种优良的重要阻燃材料，通过热重（TG）分析、差示扫描量热仪（DSC）测量和高温x射线衍射（XRD）精化研究了其热性能，并对其吸热（128.59 KJ/mol）、沿C轴热膨胀系数（αa= 1.639 × 10−5/°C）、沿a轴热膨胀系数（αa= 4.632 × 10−6/°C）和体积热膨胀系数（αV= 2.576 × 10−5/°C）进行了量化。
By using magnesium carbonate tri-hydrates (MgCO3·3H2O) as starting material, anhydrous magnesium carbonate (MgCO3) was successfully synthesized by dehydration method under high pressure for the first time. The property of as-synthesized sample was investigated by powder X-ray diffraction (XRD) and Raman spectroscopy, respectively. The high pressure synthesis was performed at the various conditions to ensure that the optimal condition is 3 GPa and 800 °C for 1 h, and it is reasonable to explain the principle of MgCO3synthesis under high pressure. The size of micro-particles observed from Scanning Electron Microscope (SEM) image exceeds to 100 μm. As a good and important flame retardant material, its thermal property is investigated by Thermogravimetric (TG) analysis, Differential Scanning Calorimeter (DSC) measurement and high temperature X-ray diffraction (XRD) refinement, and the endothermic heat (128.59 KJ/mol), the thermal expansion coefficient along c-axis (αc= 1.639 × 10−5/°C), the thermal expansion coefficient along the a-axis (αa= 4.632 × 10−6/°C) and the volume thermal expansion coefficient (αV= 2.576 × 10−5/°C) was quantified.