Tropine-Based Deep Eutectic Solvents (DES) Applied in the Alcoholysis of Polyethylene Terephthalate (PET) for Preparation of Nano Carbon Dots

Deep eutectic solvents (DES) are widely used in many fields due to their properties such as low cost, easy synthesis, low toxicity, and biodegradability. The following study selected tropine and hydrated metal salts to synthesize a series of new deep eutectic solvents as catalysts for exploring the alcoholysis reaction of PET. Then the effects of the types of DES, catalyst composition, reaction time and temperature on the alcoholysis results of PET were investigated. Using a low melting solvent of tropine/zinc acetate with a molar ratio of 4:1 as a catalyst, a reaction time of 2 h, and temperature of 180°C, the conversion rate of PET was nearly 80%, and the yield of BHET was also 80%, which was further employed to prepare nano carbon dots through simple way.