五氟乙烷灭火剂高温热解机理研究

J4 ›› 2013, Vol. 48 ›› Issue (1): 51-55.

五氟乙烷灭火剂高温热解机理研究

冒爱琴1, 2, 杨明君2, 3, 俞海云2, 张品1, 潘仁明1*

1. 南京理工大学化工学院, 江苏南京 210094;
2. 安徽工业大学材料科学与工程学院, 安徽马鞍山 243002;
3. 哥本哈根大学化学系纳米科学中心,丹麦哥本哈根 DK2100

收稿日期:2012-10-16 出版日期:2013-01-20 发布日期:2013-01-15
通讯作者: 潘仁明(1963- ), 男, 博士,研究员,博士生导师,研究方向为新型灭火剂和含能材料. Email: panrenming@163.com
作者简介:冒爱琴(1978- ),女,讲师,博士研究生,研究方向为有机氟化学合成及催化剂设计. Email:maoaiqinmaq@163.com
基金资助:
国家科技支撑项目(2008BAK40B02)

Study on thermal decomposition mechanism of pentafluoroethane fire extinguishing agent

MAO Ai-qin1,2, YANG Ming-jun2, 3, YU Hai-yun2, ZHANG Pin1, PAN Ren-ming1*

1. School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu, China;
2. School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002, Anhui, China;
3. Center for Nanoscience and Technology, Department of Chemistry, University of Copenhagen,
Copenhagen DK2100, Danmark

Received:2012-10-16 Online:2013-01-20 Published:2013-01-15

摘要/Abstract

摘要：

根据均裂的化学键类型提出了五氟乙烷(C2HF5)的9条初级裂解反应路径,采用DFT／B2LYP／6.31G*、DFT／B2LYP／6.311G**、MP2／6.31G*和MP2／6.311G**方法计算了C2F5H各裂解反应的焓变、中间态分子模型以及反应中生成的卡宾的能态。结果表明C2HF5裂解最易发生H转移反应生成C2F4;伴随H转移生成CF3CF:卡宾,F转移生成CHF:，C—C键断裂生成CF2H·和CF3·,自由基或卡宾之间相互结合生成微量的C2F6、C4F8和C4F10等气体产物。热解实验证实,C2HF5在750～850℃时主要发生脱HF反应生成C2F4,随着反应温度的增加,C2HF5分解程度提高。理论计算的C2HF5裂解产物与实验检测结果一致。

关键词: 五氟乙烷;热解机理;理论计算;热分解

Abstract:

Nine primary pyrolysis pathways of pentafluoroethane (C2HF5) are proposed based on the chemical bond types of the homolytic cleavage. The enthalpy of decomposition reaction for C2F5H, transitionstate molecules, and energies of carbenes have been studied theoretically using DFT／B2LYP／6.31G*, DFT／B2LYP／6.311G**, MP2／6.31G*, and MP2／6.311G** methods. Of a total of 9 primary reaction pathways, the decomposition of C2HF5 to form C2F4 is the most important initiation mechanism. With the Htransfer reaction to CF3CF: carbene, F-transfer reaction to CHF:, and C-C bond fission reaction to CF2H·and CF3·, a trace of products such as C2F6, C4F8 and C4F10 are produced due to the reactions between radical and carbene. It is proved by thermal decomposition that hydrogen fluoride eliminated to form C2F4 is the main reaction between 750℃ and 850℃. As the reaction temperature increases, the thermal decomposition degree of C2F5H become higher. Theoretically calculated results are consistent with the experimental observation.

Key words: pentafluoroethane; decomposition mechanism; theoretical calculation; thermal decomposition

冒爱琴1, 2, 杨明君2, 3, 俞海云2, 张品1, 潘仁明1*. 五氟乙烷灭火剂高温热解机理研究[J]. J4, 2013, 48(1): 51-55.

MAO Ai-qin1,2, YANG Ming-jun2, 3, YU Hai-yun2, ZHANG Pin1, PAN Ren-ming1*. Study on thermal decomposition mechanism of pentafluoroethane fire extinguishing agent[J]. J4, 2013, 48(1): 51-55.

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