A process for recycling polyethylene terephthalate (PET) free of metals, dyes and other additives via regeneration of ethylene glycol and dimethyl terephthalate is described. PET dissolved in dimethyl terephthalate is "unzipped" by reaction with methanol at high temperatures and pressures. Production of "original" monomers by this process decreases the amount of landfill PET and reduces the consumption of crude oil derivatives in PET production.
The module begins with an overview of the petrochemical industry including fossil fuel reserves, the distribution of fossil fuel components, and the basics of petrochemical refining and reforming. Next, the module discusses the basics of polymerization reaction chemistry including past recycling efforts. Finally, current "greener" polyester regeneration technology is highlighted.
This module includes "Notes to Instructors," a PowerPoint presentation and eight study questions and can be easily adopted for introductory polymer science as well as organic chemistry courses. Discussion can also be tailored for any general science classes to focus on global environmental challenges.
Summary prepared July 2005 by Carolyn Supplee, Department of Chemistry at Monmouth University and Rie Somlai, Department of Chemistry at Delta State University.
Dickneider, T. A. Petretec - Dupont's Technology for Polyester Regeneration. http://academic.scranton.edu/ faculty/ CANNM1/ industrial.html (accessed June 2011).