Depolymerization of polyethylene terephthalate (PET) is a promising technology for producing recycled monomers. Using a deep eutectic solvent (DES)-based catalyst, the PET glycolysis process produces bis-(2-hydroxyethylene terephthalate) (BHET). This recycled monomer reacts with isocyanate and forms polyurethane foam (PUF). The DES-based one-pot reaction is advantageous because it is a low-energy process that requires relatively lower temperatures and reduced reaction times. In this study, choline chloride/urea, zinc chloride/urea, and zinc acetate/urea based DESs were adopted as DES catalysts for glycolysis. Subsequently, the conversion of PET, BHET yield, and OH values were evaluated. Both filtered and unfiltered reaction mixtures were used as polyols for PUF polymerization after characterization of the acid and hydroxyl values of the polyols, as well as the NCO (–N=C=O) value of isocyanate. In the case of unfiltered reaction mixtures, PUF was obtained via a one-pot reaction, which exhibited higher thermal stability than PUF made from the filtered polyols. This outcome indicated that oligomeric BHET containing many aromatic moieties in unfiltered polyols contributes to the thermal stability of PUF. This environmentally friendly and relatively simple process is an economical approach for upcycling waste PET.

聚对苯二甲酸乙二醇酯 (PET) 的解聚是一种很有前景的再生单体生产技术。使用基于低共熔溶剂 (DES) 的催化剂，PET 糖酵解过程可生产双（2-羟基对苯二甲酸乙二醇酯）（BHET）。这种回收单体与异氰酸酯反应并形成聚氨酯泡沫 (PUF)。基于 DES 的一锅反应是有利的，因为它是一种低能量过程，需要相对较低的温度和较短的反应时间。本研究采用氯化胆碱/尿素、氯化锌/尿素和醋酸锌/尿素基DES作为糖酵解的DES催化剂。随后，评估了 PET 的转化率、BHET 产率和 OH 值。在对多元醇的酸值和羟基值进行表征后，过滤和未过滤的反应混合物均用作 PUF 聚合的多元醇，以及异氰酸酯的 NCO (–N=C=O) 值。在未过滤的反应混合物的情况下，PUF 是通过一锅反应获得的，与由过滤的多元醇制成的 PUF 相比，它表现出更高的热稳定性。这一结果表明，在未过滤的多元醇中含有许多芳香部分的低聚 BHET 有助于 PUF 的热稳定性。这种环境友好且相对简单的过程是一种经济的回收废旧 PET 的方法。