Doctor of Philosophy, University of Toledo, 2022, Engineering

Polyethylene terephthalate (PET) is used in packaging and textile industries such as in productions of water bottles and packaging of soft drinks. As the PET products have short lifetimes, they turn into waste rapidly. Since the market for PET products has been constantly expanding, the rate of PET waste has been increased. This may negatively affect the environment and living species. In addition, PET is produced from fossil fuels, a limited resource that should be reserved to decrease the adverse effects of its applications on the environment. Therefore, recycling has been proposed as a resolution to PET waste. Chemical recycling can decompose PET to the associated oligomers and monomers. This may provide an alternative resource for reproduction of PET and subsequently PET products. In this dissertation, hydrolysis was studied- a technique for chemically recycling of PET waste. In chemical recycling, the factors affecting the rate of PET decomposition are PET shape, PET size, reaction temperature, reaction pressure, catalyst type, catalyst concentration, and surface wetting. Few studies are reported on surface wetting. So, the main interest of this dissertation was to explore the effect of surface wetting on the rate of PET decomposition in hydrolysis reactions. In this dissertation, series of catalysts were introduced that could increase the rate of PET decomposition due to the better surface wetting of PET particles occurring with the solutions of these catalysts during the hydrolysis of PET. This effect was explored by applying a shrinking core model to interpret the kinetics data of TPA yield for calculations of reaction rate constants. These constants were correlated to the partition coefficient and distribution coefficient values of catalysts for the octanol/water system to indirectly study the PET/water system in hydrolysis. This revealed the role of functional group in catalyst structure as a determining factor for the hydrophobicity of catalyst solution (open full item for complete abstract)

Committee: Maria R. Coleman (Committee Chair); G. Glenn Lipscomb (Committee Member); Defne Apul (Committee Member); Constance A. Schall (Committee Member); Dong-Shik Kim (Committee Member) Subjects: Chemical Engineering; Chemistry; Engineering; Environmental Engineering; Environmental Science; Experiments; Materials Science; Mathematics; Mechanical Engineering; Organic Chemistry; Packaging; Plastics; Polymer Chemistry; Polymers; Sustainability