文献类型：期刊文献

英文题名：Chemical upcycling of poly(ethylene terephthalate) with binary mixed alcohols toward value-added copolyester by depolymerization and repolymerization strategy

作者：Wei, Xin[1];Zheng, Weizhong[1];Chen, Xiaofeng[1];Qiu, Jingwen[1];Sun, Weizhen[1];Xi, Zhenhao[1];Zhao, Ling[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2024

卷号：294

外文期刊名：CHEMICAL ENGINEERING SCIENCE

收录：;EI(收录号：20241715962269);WOS:【SCI-EXPANDED(收录号:WOS:001292858300001)】；

基金：This work was financially supported by the National Natural Science Foundation of China under Grant (22293064) .

语种：英文

外文关键词：PET; Mixed alcohols; Depolymerization; Repolymerization; PETG/PCTG

摘要：The glycolysis is one of the most promising chemical ways for the disposal of waste Poly(ethylene terephthalate) (PET) due to the relative mild conditions. However, several serious issues still remain to be solved, including complex monomer purification, elusive product components, and ambiguous depolymerized mechanism. Herein, the depolymerization-repolymerization strategy of PET with ethylene glycol (EG)/cyclohexane-1,4-dimethanol (CHDM) binary mixed alcohols was proposed to prepare the value-added Poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG/PCTG). Based on the one-pot depolymerization-repolymerization process, a series of amorphous PETG/PCTG with high molecular weight (M-n > 25,000 g/mol) and glass transition temperature can be prepared. The controlled depolymerization of PET into oligomers with higher molecular weight is of great importance to obtain high molecular weight PETG copolyesters according to the hierarchical process. The depolymerization mechanism of PET with mixed EG/CHDM was deeply elucidated, in which EG depolymerizes PET chains into the short ones, and CHDM undergoes transesterification with ester group on the end group of BHET monomers and oligomers with different molecular weight to substitute the ethylene glycol terephthalate (ET) units into 1,4-cyclohexanedimethanol terephthalate (CT) units. For post-consumer PET, the depolymerization-repolymerization of colorless PET bottle can form the rPETG with higher intrinsic viscosity, molecular weight, and thermal properties, superior to the PET film and colored bottles. The information in this work is of great importance for the upcycling of PET waste.