The Depolymerization of Poly(ethylene terephthalate) (PET) Using N-Heterocyclic Carbenes from Ionic Liquids

• Nahrain E. Kamber ^[1] ; Yasuhito Ysujii ^[1] ; Kate Keets ^[1] ; Robert M. Waymouth ^[1] ; Russell C. Pratt ^[2] ; Gregory W. Nyce ^[3] ; James L. Hedrick ^[3]
  1. [1] Stanford University

     Stanford University

     Estados Unidos

     
  2. [2] IBM Almaden Research Center, California
  3. [3] Almaden Research Center, California

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• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 87, Nº 5 (May), 2010, págs. 519-521
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The depolymerization of the plastic polyethylene terephthalate (PET or PETE) is described in this laboratory procedure. The transesterification reaction used to depolymerize PET employs a highly efficient N-heterocyclic carbene catalyst derived from a commercially available imidazolium ionic liquid. N-heterocyclic carbenes are potent nucleophilic organic catalysts that provide an alternative to traditional metal alkoxide depolymerization catalysts. Deprotonation of the imidazolium generates an N-heterocyclic carbene, which catalyzed the glycolysis of PET in 1 h at atmospheric pressure in refluxing anhydrous tetrahydrofuran to afford bis(2-hydroxyethyl) terephthalate (BHET). BHET is characterized by NMR and IR spectroscopy and melting point determination. This laboratory is designed for individual student work where each student depolymerizes PET prepared from a common water bottle or other source. This experiment is well suited for an introductory organic chemistry laboratory course or a polymer chemistry laboratory course.