Kirshanov Kirill A, Toms Roman V, Balashov Mikhail S, Golubkov Sergey S, Melnikov Pavel V, Gervald Alexander Yu
M.V. Lomonosov Institute of Fine Chemical Technologies, MIREA-Russian Technological University, Moscow 119571, Russia.
A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Str., Moscow 119334, Russia.
Polymers (Basel). 2023 Jul 24;15(14):3146. doi: 10.3390/polym15143146.
Polymer composites with various recycled poly(ethylene terephthalate)-based (PET-based) polyester matrices (poly(ethylene terephthalate), copolyesters, and unsaturated polyester resins), similar in properties to the primary ones, can be obtained based on PET glycolysis products after purification. PET glycolysis allows one to obtain bis(2-hydroxyethyl) terephthalate and oligo(ethylene terephthalates) with various molecular weights. A kinetic model of poly(ethylene terephthalate) homogeneous glycolysis under the combined or separate action of oligo(ethylene terephthalates), bis(2-hydroxyethyl) terephthalate, and ethylene glycol is proposed. The model takes into account the interaction of bound, terminal, and free ethylene glycol molecules in the PET feedstock and the glycolysis agent. Experimental data were obtained on the molecular weight distribution of poly(ethylene terephthalate) glycolysis products and the content of bis(2-hydroxyethyl) terephthalate monomer in them to verify the model. Homogeneous glycolysis of PET was carried out at atmospheric pressure in dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) solvents with catalyst based on antimony trioxide (SbO) under the action of different agents: ethylene glycol at temperatures of 165 and 180 °C; bis(2-hydroxyethyl) terephthalate at 250 °C; and oligoethylene terephthalate with polycondensation degree 3 at 250 °C. Homogeneous step-by-step glycolysis under the successive action of the oligo(ethylene terephthalate) trimer, bis(2-hydroxyethyl) terephthalate, and ethylene glycol at temperatures of 250, 220, and 190 °C, respectively, was also studied. The composition of products was confirmed using FTIR spectroscopy. Molecular weight characteristics were determined using gel permeation chromatography (GPC), the content of bis(2-hydroxyethyl) terephthalate was determined via extraction with water at 60 °C. The developed kinetic model was found to be in agreement with the experimental data and it could be used further to predict the optimal conditions for homogeneous PET glycolysis and to obtain polymer-based composite materials with desired properties.
基于纯化后的聚对苯二甲酸乙二酯（PET）醇解产物，可以制备出具有各种回收聚对苯二甲酸乙二酯基（PET基）聚酯基体（聚对苯二甲酸乙二酯、共聚酯和不饱和聚酯树脂）的聚合物复合材料，其性能与原始材料相似。PET醇解能够得到不同分子量的对苯二甲酸双（2-羟乙基）酯和聚对苯二甲酸乙二酯低聚物。提出了在聚对苯二甲酸乙二酯低聚物、对苯二甲酸双（2-羟乙基）酯和乙二醇的联合或单独作用下，聚对苯二甲酸乙二酯均相醇解的动力学模型。该模型考虑了PET原料和醇解剂中键合、末端和游离乙二醇分子之间的相互作用。获得了聚对苯二甲酸乙二酯醇解产物的分子量分布及其对苯二甲酸双（2-羟乙基）酯单体含量的实验数据，以验证该模型。PET的均相醇解在常压下于二甲基亚砜（DMSO）和N-甲基-2-吡咯烷酮（NMP）溶剂中进行，以三氧化二锑（SbO）为催化剂，在不同试剂作用下进行：乙二醇在165和180℃温度下；对苯二甲酸双（2-羟乙基）酯在250℃下；以及缩聚度为3的聚对苯二甲酸乙二酯低聚物在250℃下。还研究了在250、220和190℃温度下，分别在聚对苯二甲酸乙二酯三聚体、对苯二甲酸双（2-羟乙基）酯和乙二醇的连续作用下的均相逐步醇解。使用傅里叶变换红外光谱（FTIR）对产物组成进行了确认。使用凝胶渗透色谱（GPC）测定分子量特性，通过在60℃用水萃取来测定对苯二甲酸双（2-羟乙基）酯的含量。发现所建立的动力学模型与实验数据一致，可进一步用于预测PET均相醇解的最佳条件，并获得具有所需性能的聚合物基复合材料。
