Waste <scp>PET</scp>‐Derived Sustainable and Efficient Hydrogel for Removal of Fe³⁺

ABSTRACT Plastic waste is one of the most crucial environmental problems facing our world. Although studies are conducted on various functional materials, hydrogel research on this subject is relatively rare. This study presents a method for the advanced recycling of waste polyethylene terephthalate (PET) bottles. Initially, a water‐soluble oligomeric products are obtained through PET aminolysis using triethylenetetramine (TETA). Then, this oligomeric structure was cross‐linked with polyethylene glycol diglycidyl ether (PEGDE) in an aqueous environment to form a 3D polymeric network. The obtained hydrogel has a rich amine group content, which makes it hydrophilic and suitable for use as an adsorbent. In particular, these groups can bind to the empty d‐orbitals of transition metals via coordination bonds and trap the metal inside. TGA and DSC were used for thermal analysis of the hydrogel; FTIR and 1 H NMR for structural characterization of the aminolyzed PET and hydrogel; and UV/Vis spectrophotometry for determining the Fe 3+ ion concentration. At the maximum adsorption level, 1 g of the hydrogel adsorbed 124.66 mg of Fe 3+ ions, corresponding to a 99.55% adsorption efficiency. This study offers a useful approach in terms of being both cost‐effective and efficient for the problem of waste plastic and water pollution.