Glycolysis of polyethylene terephthalate: Magnetic nanoparticle CoFe2O4 catalyst modified using ionic liquid as surfactant

The catalytic effect of nanoparticles was significantly affected by its size and surface property. In this work, a series of ionic liquids were synthesized and used as surfactant to modify CoFe 2 O 4 MNP. XRD, FT-IR, TEM and VSM were performed to characterize modified CoFe 2 O 4 . The modified CoFe 2 O 4 MNP with average size of 7 nm was obtained and it was so well dispersed in ethylene glycol that ethylene glycol based magnetic fluid was obtained. Modified CoFe 2 O 4 MNP was used as catalyst for glycolysis of PET and showed excellent catalytic effect. The influence of ionic liquids surfactant and experimental factors on glycolysis were investigated. Under optimal condition, PET (5 g), catalyst (CoFe2O4/C10-OAC, 0.1 g) and EG (25 g) at 195 °C for 2.5 h, the PET conversion was 100% and BHET yield was 95.4%. More importantly, this catalyst can be collected by external magnetic field and its catalytic effect did not obviously decrease after it was reused for ten times. This work provided a new type of highly efficient catalyst of glycolysis of PET.