Superparamagnetic gamma -Fe sub(2)O sub(3) nanoparticles as an easily recoverable catalyst for the chemical recycling of PET

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 16; no. 1; pp. 279 - 286
• Main Authors: Bartolome, Leian, Imran, Muhammad, Lee, Kyoung G, Sangalang, Arvin, Ahn, Jeong Keun, Kim, Do Hyun
• Format: Journal Article
• Language: English
• Published: 01.12.2013
• Subjects: Catalysts; Decantation; Glycolysis; Monomers; Nanoparticles; Polyethylene terephthalates; Recycling; Terephthalate
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/c3gc41834k

There have been numerous studies to develop catalysts for the chemical recycling of poly(ethylene terephthalate) (PET) viaglycolysis. However, in the field of PET glycolysis, only a few have attempted to recover and reuse the catalysts. This research utilized easily recoverable superparamagnetic gamma -Fe sub(2)O sub(3) nanoparticles as a reusable catalyst for PET glycolysis. gamma -Fe sub(2)O sub(3) nanoparticles were produced by calcining Fe sub(3)O sub(4) nanoparticles prepared by the co-precipitation method. The produced gamma -Fe sub(2)O sub(3) nanoparticles had an average size of 10.5 plus or minus 1.4 nm, and a very high surface area reaching 147 m super(2) g super(-1). Its superparamagnetic property was also confirmed. Glycolysis reactions were carried out, and the gamma -Fe sub(2)O sub(3) catalysts were recovered after the reactions by simple magnetic decantation. The use of magnetic iron oxide allowed the easy recovery of the catalyst from the glycolysis products. At 300 degree C and a 0.05 catalyst/PET weight ratio, the maximum bis(2-hydroxyethlyl) terephthalate (BHET) monomer yield reached more than 90% in 60 min. At 255 degree C and a 0.10 catalyst/PET weight ratio, the BHET yield reached more than 80% in 80 min. The catalyst was reused 10 times, giving almost the same BHET yield each time.