氯化天然橡胶在热空气中脱氯化氢的反应动力学

Kinetics of dehydrochlorination reaction of chlorinated natural rubber under hot air

采用电导率法研究了氯化天然橡胶(CNR)在热空气中脱氯化氢的反应动力学。结果表明,CNR脱氯化氢反应过程可以分为3个阶段:诱导期、加速期和恒速期。在第1阶段,脱氯化氢速率很慢,产生的氯化氢量几乎为0;在第2阶段,脱氯化氢速率逐渐加快;在第3阶段,脱氯化氢速率恒定,反应级数为0,表观活化能为50.68kJ/mol。随反应温度升高,脱氯化氢残余物中的共轭双键数量增多。CNR分子中与甲基相连的碳氯键比其他碳氯键稳定。

The conductance method was employed to study the kinetics of dehydrochlorination （DHC） reaction of chlorinated natural rubber （CNR） under hot air. The results showed that the reaction included three stages： inductive DHC reaction, quick DHC reaction and invariable DHC reaction. In the first stage, the rate of DHC reaction was very slow, and the amount of hydrogen chloride come from CNR was very little. In the second period, the rate of DHC reaction accelerated gradually. During the third stage, the rate of DHC reaction was invariable, and the reaction order was 0, and the apparent activation energy was 50.68 kJ/mol. The number of conjugate double bond in the residue increased with the increment Of reaction temperature. The C-Cl bond which was joined to methyl was more stable than the other C-Cl bond.