This work studies the chlorine (Cl) release during the esterification of terephthalic acid (TPA) and ethylene glycol (EG) due to the addition of different amounts of polyvinyl chloride (PVC) that emulates its presence as an impurity. With the aim to explore the possible effects of PVC presence and its dehydrochlorination during the syntheses of bis(2-hydroxyethyl) terephthalate (BHET) and with the aid of a mathematical model, the evolution releasing of Cl during PVC dehydrochlorination is analyzed. Theoretical results present a good correlation with experimental data that indicate the presence of Cl in the composition of the final product because the dehydrochlorination is incomplete. Additionally, the model predicts the temperature in that Cl can be completely released avoiding its presence in BHET. These kinds of studies are of particular interest when products with a high degree of purity are required, and Cl is detrimental to end applications.

中文翻译：

---

在 PVC 存在下合成 BHET 过程中氯释放的理论-实验研究

这项工作研究了在对苯二甲酸 (TPA) 和乙二醇 (EG) 的酯化过程中，由于添加了不同量的聚氯乙烯 (PVC) 来模拟其作为杂质的存在，从而释放氯 (Cl)。为了探讨对苯二甲酸双（2-羟乙基）酯 (BHET) 合成过程中 PVC 的存在及其脱氯化氢的可能影响，并借助数学模型，分析了 PVC 脱氯化氢过程中 Cl 的释放演变。理论结果与实验数据具有良好的相关性，表明由于脱氯化氢不完全，最终产品的组成中存在 Cl。此外，该模型预测温度，因为 Cl 可以完全释放，避免其存在于 BHET 中。