Publication Date

Fall 2010

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemical and Materials Engineering

Advisor

Melanie McNeil

Keywords

Epoxy, Green Chemistry, Organocatalysis, PET, Recycling

Subject Areas

Plastics; Polymer Chemistr; Materials Science

Abstract

This study focuses on the organocatalytic decomposition of polyethylene terephthalate (PET) using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) to form a diverse library of aromatic amides. The reaction scheme was specifically designed to use low reaction temperatures (>150oC) and avoid using solvents during the reaction to provide a more environmentally friendly process. Of all the amines tested, PET aminolysis with aliphatic and aromatic amines demonstrated the best performance with yields higher than 72%. PET aminolysis with click functionalized and non-symmetric reagents facilitated attack on certain sites on the basis of reactivity. Finally, the performance of the PET degradation reactions with secondary amine and tertiary amine functionalized reagents yielded mixed results due to complications with isolating the product from the crude solution. Four of the PET-based monomers were also selected as modifiers for epoxy hardening to demonstrate the ability to convert waste into monomers for high-value applications. The glass transition temperatures, obtained using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) of the epoxy composite samples treated with the PET-based monomers, were generally higher in comparison to the samples cured with the basic diamines due to the hydrogen bonding and added rigidity from the aromatic amide group. Developing these monomers provides a green and commercially viable alternative to eradicating a waste product that is becoming an environmental concern.

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