CIESC Journal ›› 2022, Vol. 73 ›› Issue (10): 4762-4768.DOI: 10.11949/0438-1157.20220725

• Process safety • Previous Articles     Next Articles

Experimental and theoretical study on the pyrolysis mechanism of (C2F5)3N

Tianshui LIANG(), Xinke WANG, Dezhi LIU, Wei ZHONG()   

  1. School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, Henan, China
  • Received:2022-05-19 Revised:2022-07-22 Online:2022-11-02 Published:2022-10-05
  • Contact: Wei ZHONG

全氟三乙胺热解机理的实验与理论研究

梁天水(), 王新科, 刘德智, 钟委()   

  1. 郑州大学力学与安全工程学院,河南 郑州 450001
  • 通讯作者: 钟委
  • 作者简介:梁天水(1981—),男,博士,教授,liangtsh@zzu.edu.cn
  • 基金资助:
    国家自然科学基金项目(51874258)

Abstract:

Fluorine amines are one of the most promising nitrogen-containing compounds as halon substitutes. As a typical fluorine amine, perfluorotriethylamine has good fire-extinguishing effect. In order to reveal the pyrolysis mechanism of (C2F5)3N, its pyrolysis products under different temperature conditions are obtained by using GC-MS, and then the pyrolysis reaction paths are theoretically calculated by using Gaussian. The results show that the initial pyrolysis temperature of (C2F5)3N is about 600℃, and the complete pyrolysis is around 750℃, by keeping the residence time at 10 s. The pyrolysis products are C4F9N, C3F7N, C2F6 and C3F8. The volume fraction of C4F9N is the largest at a low pyrolysis temperature, while the volume fraction of C3F7N is the largest at a high pyrolysis temperature. In the calculation of the pyrolysis reaction path of (C2F5)3N, there is one reaction pathway would generate C3F8 after the breaking of C—C bond in the (C2F5)3N molecule. In another pyrolysis reaction path of (C2F5)3N, C2F6 and the stable product C4F9N would be generated after the breaking of C—N bond. The breaking of C—N bond in (C2F5)3N would produce an unstable product N(C2F5)2, the followed breaking of the C—C bond will generate C3F7N. The main pyrolysis products of (C2F5)3N are C4F9N and C3F7N, the two products have CN double bonds and can more easily interact with the combustion active.

Key words: (C2F5)3N, pyrolysis, Gaussian calculation, reaction path, mechanism

摘要:

氟胺类物质是最有希望作为哈龙替代品的含氮化合物之一,全氟三乙胺作为典型的氟胺类物质具有良好的灭火效果。为研究全氟三乙胺热解机理,在管式加热炉内对全氟三乙胺进行热分解,通过GC-MS分析全氟三乙胺在不同温度条件下的热解产物,并用Gaussian软件对其热解反应路径进行理论计算。结果表明:保持停留时间为10 s,全氟三乙胺的初始热解温度为600℃,750℃完全热解,热解产物有C4F9N、C3F7N、C2F6和C3F8,热解温度较低时C4F9N体积分数最大,热解温度较高时C3F7N体积分数最大。在全氟三乙胺热解反应路径计算中,全氟三乙胺分子中的C—C键断裂后存在1条反应路径,可生成实验产物中的C3F8;全氟三乙胺分子的C—N键断裂后存在3条反应路径,可生成实验产物中的C3F7N、 C4F9N和C2F6。全氟三乙胺热解后产生的CF3自由基可与H、OH自由基发生反应,从而产生灭火作用。此外,其热解产物C4F9N和C3F7N具有CN双键,更容易与燃烧活泼自由基·OH、·H发生化学作用,对研究全氟三乙胺的灭火机理具有十分重要的意义。

关键词: 全氟三乙胺, 热解, 高斯计算, 反应路径, 机理

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