This study employed titanium catalysts to degrade low‐quality PET (polyethylene terephthalate) bottle flakes and subsequently re‐polymerized the degradation solution to investigate whether the titanium catalyst could restore the physical and chemical properties of the degraded PET bottle flakes. The reaction process of property restoration was characterized using GPC, DSC, ICP, NMR, and so forth. The mechanism of titanium catalyst‐catalyzed PET polymerization was explored through simulation calculations. The results indicate that the waste PET bottle flakes have been restored to the standard of first‐grade PET bottle flakes under the degradation and re‐polymerization processes with the aid of dibutyl ethylene glycol titanate catalysts. The Ti ion in the recycled PET is stable and the metal ion leached from the restored PET in the strong acid environment meets food‐grade safety requirements. This study is expected to provide a new way for recycling waste PET bottle flakes.

中文翻译：

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Ti 基催化剂恢复废瓶级聚对苯二甲酸乙二醇酯的性质


本研究采用钛催化剂降解劣质 PET（聚对苯二甲酸乙二醇酯）瓶片，随后对降解溶液进行再聚合，以研究钛催化剂是否能恢复降解的 PET 瓶片的物理和化学性质。利用GPC、DSC、ICP、NMR等对性质恢复的反应过程进行表征。通过模拟计算探索钛催化剂催化 PET 聚合的机理。结果表明，在乙二醇钛酸二丁酯催化剂的帮助下，废旧 PET 瓶片在降解和再聚合过程中已恢复到一级 PET 瓶片的标准。回收 PET 中的钛离子稳定，在强酸环境中从回收的 PET 中浸出的金属离子符合食品级安全要求。这项研究有望为回收废弃 PET 瓶片提供一种新方法。