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›› 2011, Vol. 11 ›› Issue (3): 448-451.

• 过程与工艺 • 上一篇    下一篇

添加液氮对芳纶1414合成的影响

卢俨俨 张涛 骞伟中 罗国华 庹新林 魏飞   

  1. 清华大学化工系 清华大学化工系 清华大学化工系 清华大学化学工程系 清华大学化学工程系 清华大学化工系
  • 收稿日期:2010-12-14 修回日期:2011-03-03 出版日期:2011-06-20 发布日期:2011-06-20
  • 通讯作者: 骞伟中

Effect of Liquid Nitrogen Addition on Synthesis of Poly(p-phenylene terephthalamide)

LU Yan-yan ZHANG Tao， QIAN Wei-zhong LUO Guo-hua TUO Xin-lin， WEI Fei   

  1. Department of Chemical Engineering, Tsinghua University Department of Chemical Engineering, Tsinghua University Department of Chemical Engineering, Tsinghua University Department of Chemical Engineering, Tsinghua University Department of Chemical Engineering, Tsinghua University Department of Chemical Engineering, Tsinghua University
  • Received:2010-12-14 Revised:2011-03-03 Online:2011-06-20 Published:2011-06-20
  • Contact: QIAN Wei-zhong

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摘要： 提出了添加液氮以促进芳纶1414合成体系换热的方法，即将溶液的最高温度控制在2.5℃以下，同时在反应初期(2~11 min)使温度下降速率为1.3℃/min. 与冰水浴间接换热相比，本法可获得更低的反应温度与更快的移热速率，有利于抑制缩聚反应初期的暴聚现象. 分析结果显示，液氮的加入与相变还可促进反应物剧烈混合，传质效果的改善也有利于显著提高产品质量，最终得到了比浓对数粘度高达6.9 dL/g的产品.

关键词: 芳纶1414, 液氮, 相变, 传热

Abstract: A method to enhance the heat removal in the synthesis system of poly(p-phenylene terephthalamide) (PPTA) by adding liquid nitrogen was proposed. The phase transition of liquid nitrogen is effective to control the maximal temperature of the system below 2.5℃. The decreasing rate of temperature in the initial polymerization stage (2~11 min) is 1.3℃/min. Compared with the indirect heat removal by water-ice bath, this absorbs reaction heat in large amount and quickly, which is crucial to the temperature control for this highly exothermic reaction, especially for the scale up. In addition, the phase transition of liquid nitrogen provides the turbulent mixing of the reactants in the system, which improve the mass transfer and favors the increase in the quality of the product, evidenced by thermogravimetry, XRD and Raman spectroscopy. The viscosity of final product is up to 6.9 dL/g, suggesting its high quality.

Key words: poly(p-phenylene terephthalamide), liquid nitrogen, phase transition, heat transfer

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