Screening of Different Titanium (IV) Catalysts in the Synthesis of Poly(ethylene terephthalate)

The polycondensation of bis(hydroxyethylene) terephthalate and its oligomers to PET catalyzed by different chelated and non‐chelated titanium catalysts in a lab‐scale stirred‐tank reactor and differential scanning calorimeter were investigated. Different titanium compounds showed different activity and selectivity. The nature of catalyst ligands plays an important role in catalyst efficiency. Non‐chelated titanium derivatives were more active and less selective. Reaction progress is characterized by an initial inhibition period depending on the type of catalyst. The original titanium compounds used are precursors and are probably activated by a ligand exchange reaction. magnified image