偶氮二环己基甲腈及其苯胺溶液热危险性研究

Thermal hazards of 1,1'-Azobis(cyclohexane-1-carbonitrile)and its solution in aniline

为研究偶氮二环己基甲腈（ACCN）在相关工艺过程中的热危险性,采用差示扫描量热仪（DSC）对ACCN及其苯胺（AN）溶液进行动态测试,发现溶于AN后,ACCN的起始分解温度前移,热稳定性变差。利用Friedman法得到,转化率为0.15-0.8时ACCN的AN溶液的活化能平均值为121 kJ/mol。采用Coats-Redfern法研究ACCN的AN溶液的热分解机理,得到其积分动力学机理函数。采用绝热加速量热仪（ARC）对ACCN以及ACCN＋AN进行绝热分解测试,在热惯量修正的基础上,得到其TD24（最大反应速率到达时间为24 h的温度）分别为79.3℃与68.1℃,同样得到ACCN在AN中热稳定性变差的结论。因此,在相关工艺要求ACCN与AN溶剂混合使用的场合,必须严格控制温度,预防热爆炸事故的发生。

In order to study the thermal hazard of ACCN in the associated process, ACCN and its solu- tion in AN were tested by DSC in dynamic mode. The results showed ACCN started to decompose at lower temperature when dissolved into aniline, implying that its thermal stability was reduced. The thermal decomposition process of ACCN-AN system was analyzed by Friedman method, which showed that when conversion ranged from 0. 15 to 0. 8, the average activation energy was 121 kJ/mol. Coats-Redfern method was employed to calculate the reaction mechanism, resulting in an integral mechanism function. Moreover, ARC was employed to test the adiabatic decomposition of ACCN and ACCN ＋ AN. After correction by the thermal inertia, temperatures at which 0 （time to maximum rate under adiabatic condition） is 24 hours were predicted as 79.3 ℃ and 68. 1 ℃ for ACCN and ACCN ＋ AN respectively. It came to the same con- clusion that ACCN＇s thermal stability deteriorated when dissolved into aniline. Therefore, if the relevant process requires ACCN to be mixed with aniline, the temperature must be strictly controlled to prevent thermal explosion.