The kinetics of the synthesis of tert-butyl peroxy-2-ethylhexanoate were investigated in a capillary microreactor. TBPEH was synthesized from 2-ethylhexanoyl chloride and tert-butyl hydroperoxide in the presence of a strong base, using the Schotten–Baumann method. The peroxyesterification reaction is always in competition with the unwanted acid chloride hydrolysis. The synthesis was carried out with and without a phase-transfer catalyst. The non-catalyzed reaction showed a low rate, which could be incremented by increasing the temperature and the liquid–liquid interfacial area or by using KOH instead of NaOH as base. The peroxyesterification and hydrolysis rates increased with temperature. However, the use of KOH or the increase in interfacial area accelerated only the peroxyester formation, increasing the selectivity towards the desired product. The addition of a PTC enhanced the peroxyesterification rate without changing the hydrolysis rate. Among the screened PTCs, quaternary ammonium salts with longer alkyl chains gave the best performance, up to 25 times faster peroxyesterification. The rate increase was proportional to the PTC amount. The interfacial area had the same effect as in the non-catalyzed reaction. Because of the tremendous increase in the reaction speed due to the PTC, the rate increased with slug velocity. At low slug velocity the reactants in the thin liquid film surrounding the droplets in the capillary are depleted and the peroxyesterification rate decreases. A reaction mechanism is proposed that explains the experimental observation. The corresponding kinetic model predicts the observed reaction rate with 10% accuracy.

中文翻译：

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在毛细管微反应器中使用相转移催化剂进行 Schotten-Baumann 合成过氧酯的动力学研究和建模

在毛细管微反应器中研究了合成过氧化 2-乙基己酸叔丁酯的动力学。TBPEH 由 2-乙基己酰氯和叔丁基合成-丁基氢过氧化物在强碱存在下，使用 Schotten-Baumann 方法。过氧酯化反应总是与不需要的酰氯水解竞争。合成是在有和没有相转移催化剂的情况下进行的。非催化反应显示出低速率，可以通过增加温度和液-液界面面积或使用 KOH 代替 NaOH 作为碱来增加速率。过氧酯化和水解速率随温度增加。然而，KOH 的使用或界面面积的增加仅加速了过氧酯的形成，从而提高了对所需产物的选择性。PTC 的加入提高了过氧酯化速率，但不改变水解速率。在筛选出的 PTC 中，具有较长烷基链的季铵盐具有最佳性能，过氧酯化速度最多可提高 25 倍。速率增加与PTC量成正比。界面面积具有与非催化反应相同的效果。由于 PTC 引起的反应速度大幅增加，反应速度随着段塞速度的增加而增加。在低段塞速度下，毛细管中液滴周围的薄液膜中的反应物耗尽，过氧酯化速率降低。提出了解释实验观察的反应机制。相应的动力学模型以 10% 的准确度预测了观察到的反应速率。界面面积具有与非催化反应相同的效果。由于 PTC 引起的反应速度大幅增加，反应速度随着段塞速度的增加而增加。在低段塞速度下，毛细管中液滴周围的薄液膜中的反应物耗尽，过氧酯化速率降低。提出了解释实验观察的反应机制。相应的动力学模型以 10% 的准确度预测了观察到的反应速率。界面面积具有与非催化反应相同的效果。由于 PTC 引起的反应速度大幅增加，反应速度随着段塞速度的增加而增加。在低段塞速度下，毛细管中液滴周围的薄液膜中的反应物耗尽，过氧酯化速率降低。提出了解释实验观察的反应机制。相应的动力学模型以 10% 的准确度预测了观察到的反应速率。提出了解释实验观察的反应机制。相应的动力学模型以 10% 的准确度预测了观察到的反应速率。提出了解释实验观察的反应机制。相应的动力学模型以 10% 的准确度预测了观察到的反应速率。