Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (19): 2045-2048.DOI: 10.6023/A12050258 Previous Articles     Next Articles

Full Papers


吴智诚, 潘丹梅, 陈志, 林璋   

  1. 中国科学院福建物质结构研究所 结构化学国家重点实验室 福州 350002
  • 投稿日期:2012-05-30 发布日期:2012-08-30
  • 通讯作者: 林璋
  • 基金资助:
    项目受国家重点基础研究发展计划(973)(No. 2010CB933501和2007CB936703);杰出青年基金(No. 21125730)和国家自然科学基金(Nos. 20803082, 20971123, 21103191)资助.

Synthesis of Flaky Flame-retardant Magnesium Hydroxide with High Dispersion

Wu Zhicheng, Pan Danmei, Chen Zhi, Lin Zhang   

  1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002
  • Received:2012-05-30 Published:2012-08-30
  • Supported by:
    Project supported by the National Basic Research Program (973) of China (Nos. 2010CB933501 and 2007CB936703), the Outstanding Youth Fund (No. 21125730) and National Natural Science Foundation of China (Nos. 20803082, 20971123, 21103191).

In this study, Flaky magnesium hydroxide with highly dispersion was prepared from light-burned magnesia by hydration hydrothermal method. The influence of different hydration temperature, hydration time, hydrothermal time and dispersant system on the morphology of magnesium hydroxide material was investigated systematically. The morphology, phase composition and specific surface area of magnesium hydroxide were investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and accelerated surface area and porosimetry (ASAP). The highly dispersed flaky flame-retardant magnesium hydroxide was further surface modified and then its flame retardation property was tested. Results demonstrated that the light-burned magnesium oxide could completely transform to magnesium hydroxide at 90 ℃ for 1 h hydration, and the products were uniform hexagonal flake with thickness about 20~30 nm. When the hydrated magnesium hydroxide further hydrothermal reacted at 160 ℃ for 23 h, the crystal structure changed. According to the XRD pattern, (100) face appeared more, while the stronger (001) face became less visible, and the ratio of I001/I101 was about 1.80. It indicated that controlling hydrothermal reaction condition would change the growth direction of magnesium hydroxide crystal, and the surface polarity and internal stress of the crystals decreased when the hydrothermal reaction time was extended. SEM observation indicated that the thickness of magnesium hydroxide hexagonal flake increased to 80~100 nm after hydrothermal reaction. Moreover, the dispersion of the product was enhanced and the aggregation was reduced after further surface modification and regulation by dispersant. Thus, the specific surface area was 9.1668 m2/g. When the modified highly dispersed magnesium hydroxide was added to the PVC composite system, the oxygen index of the system was 27.3. Under the same condition, the oxygen index of ordinary magnesium hydroxide and calcium carbonate were 25.7 and 22.7, respectively. This result declared that the addition of highly dispersed magnesium hydroxide could enhance the flame retardancy of PVC composite system.

Key words: hydrothermal method, flame retardant, magnesium hydroxide, dispersing agent