Lewis Acid–Base Synergistic Catalysis for Polyethylene Terephthalate Degradation by 1,3-Dimethylurea/Zn(OAc)₂ Deep Eutectic Solvent

Abstract

Deep eutectic solvents (DESs) become more attractive in the catalytic field due to their biodegradation, low toxicity, and designability. This study focused on the active sites and influencing factors of 1,3-dimethylurea (1,3-DMU) based DESs in the polyethylene terephthalate (PET) glycolysis process. It is found that the active site of urea derivatives is the amino group, and the basicity and steric hindrance of the amino group affect its catalytic activity. Additionally, the mechanism of PET glycolysis reaction catalyzed by DES was investigated. The outstanding catalytic activity of DES can be attributed to the synergistic effect of acid and base formed between metal salts and 1,3-DMU. Under the optimization conditions, PET (5.0 g), ethylene glycol (20.0 g), and catalyst (n(1,3-DMU)/n(Zn­(OAc)2) 4/1, 0.25 g) at 190 °C for 20 min, the PET conversion is up to 100%, and the yield of bis­(hydroxyalkyl) terephthalate (BHET) is 82%. Furthermore, the kinetic research shows that the glycolysis of PET follows the shrink-core model, and the apparent activity energy is 148.89 kJ/mol.

An efficient multicomponent synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by a magnetic nanoparticle supported Lewis acidic deep eutectic solvent

“…1,2 Among them, Lewis acidic deep eutectic solvents (LADESs) have been intensively studied as efficient media for organic syntheses. 3,4 The stable and efficient LADESs can afford the desired products in high yield and selectivity against the conventional metal halide catalysts. [5][6][7][8][9][10][11] However, some drawbacks such as the use of a large amount of LADESs, difficulty in catalyst recovery and product separation, which can cause environmental pollution and a high-cost to the procedure, limit their application in industrial processes.…”

Polyethylene Terephthalate Degradation by Microalga Chlorella vulgaris Along with Pretreatment

“…The current research was aimed to compare the plastic biodegradation with or without Pretreatment. It was anticipated that physical treatment might enhance the biodegradation rate [28].…”

“…Different microorganisms like algae, fungi, and bacteria produce different chemicals like mucilaginous substances by algae, while bacteria and fungi produce laccases, hydrolases, PETases, peroxidases, lipases, which help in cleaving the polymer structure into more straightforward and available form for microbes. Laccases decompose the hydrocarbon group of polyethylene when plastics films are incubated with them; the average molecular weight of polymer declines up to 10 to 20 % as an outcome [28,29,35].…”

“…Some microbial strains have the potential to degrade the plastic. Thus, such strains can be employed degradation of polymer by providing an appropriately controlled environment [27][28][29].…”

Degradation of polycarbonate to produce bisphenol A catalyzed by imidazolium-based DESs under metal-and solvent-free conditions

“…In recent decades, DESs as a reaction medium have attracted widespread attention, making them have broad application prospects in industrial production. 39 Although their application as catalysts in PC degradation has not been reported, DESs such as urea/metal salt, ChCl/Zn(Ac) 2 and 1,3-dimethylurea/Zn(OAc) 2 have been successfully used for the alcoholysis of polyethylene terephthalate (PET), [40][41][42] and achieved some good results. At present, DESs are mainly made of choline chloride (ChCl) and urea or certain metal salts, but almost no other types of DESs have been reported.…”