高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (2): 20230398.doi: 10.7503/cjcu20230398

• 物理化学 • 上一篇    下一篇

硝酸酯键断裂触发的含能增塑剂DNTN多阶热分解机理

曹华文, 唐秋凡, 屈蓓, 霍欢, 郑启龙, 曹意林, 李吉祯()   

  1. 西安近代化学研究所, 西安 710065
  • 收稿日期:2023-09-05 出版日期:2024-02-10 发布日期:2023-12-07
  • 通讯作者: 李吉祯 E-mail:jizhenli@126.com
  • 基金资助:
    国家自然科学基金(22205176)

Multi-stage Thermal Decomposition Mechanism of Energetic Plasticizer DNTN Triggered by Cleavage of the Nitrate Ester Bond

CAO Huawen, TANG Qiufan, QU Bei, HUO Huan, ZHENG Qilong, CAO Yilin, LI Jizhen()   

  1. Xi’an Modern Chemistry Research Institute,Xi’an 710065,China
  • Received:2023-09-05 Online:2024-02-10 Published:2023-12-07
  • Contact: LI Jizhen E-mail:jizhenli@126.com
  • Supported by:
    the National Natural Science Foundation of China(22205176)

摘要:

采用反应分子动力学模拟、 固相原位红外测试和同步热分析-红外-质谱联用技术相结合的方法对 2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四硝酸酯(DNTN)的热分解过程进行了研究, 分析了其热分解气体产物和固相产物, 阐明了其热分解机理. 结果表明, DNTN的分解分为3个阶段: 第一阶段为诱导分解阶段, 温度区间为127~147 ℃, DNTN发生部分O—N键的断裂, 释放少量的NO2气体; 第二阶段在147~220 ℃之间, DNTN快速分解, 发生硝基基团脱去和季碳骨架的分解, 并且伴随小环结构的生成和裂解, 释放大量的NO2和CO2等气体, 同时放出大量的热; 第三阶段为240~350 ℃, DNTN剩余固态产物在高温下热解, 释放少量的CO2, 并且在300 ℃后剩余的固相物质会进一步反应生成氰基.

关键词: 硝酸酯, 2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四硝酸酯, 多级热分解, 热分解反应机理, 反应分子动力学

Abstract:

2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol tetranitrate(DNTN) is energetic material, which is the densest nitrate. The unclear thermal decomposition mechanism of DNTN has seriously hindered its application in propellants. The thermal decomposition process of DNTN was investigated by a combination of reactive force field molecular dynamics(ReaxFF MD) simulation, solid-phase in situ infrared spectroscopy(in situ IR) and TG-DSC- FTIR-MS simultaneous techniques, and the gas and solid products of the thermal decomposition were analysed, the thermal decomposition mechanism was elucidated. The results showed that the decomposition of DNTN was revealed that the process occurred in three stages. During the first stage from 127 ℃ to 147 ℃, the O—N bond in DNTN was partially broken, releasing a minor amount of NO2 gas. In the second stage, between 147 ℃ and 220 ℃, DNTN underwent rapid decomposition, removing the nitro groups and decomposing the quaternary carbon skeleton, accompanied by the formation and cleavage of the microcyclic structure, releasing a large amount of gases such as NO2 and CO2, and at the same time emitting a large amount of heat. The third stage, taking place within the temperature range of 240—350 ℃, involved the high temperature pyrolysis of the remaining solid product of DNTN, which resulted in a limited release of CO2 gas, and above 300 ℃, the remaining solid phase material would further react to result in the production of cyano. In this paper, the thermal decomposition mechanism of DNTN was illustrated from a multistage perspective, which had important guiding significance for its application in propellants and the follow-up research on stability mechanism.

Key words: Nitrate ester, 2, 3-Bis(hydroxymethyl)-2, 3-dinitro-1, 4-butanediol tetranitrate, Multistage thermal decomposition, Thermal decomposition mechanism, ReaxFF molecular dynamics

中图分类号: 

TrendMD: