Conversion of waste bottles’ PET to a hydrogel adsorbent via PET aminolysis

To ensure sustainable use of natural resources and circulation of materials, efficient methods of waste plastic conversion into value chemicals and scenarios for utilization of the latter are increasingly demanded. Here, we propose a method of waste PET bottles conversion to cross-linked hydrogels through PET aminolysis using tri- and tetraamines as a method of plastic waste valorization. Water-soluble oligomeric products of PET aminolysis were cross-linked in water using diglycidyl ether to get mechanically stable hydrogels that show typical polyelectrolyte behavior of polycations. PET-derived hydrogels abundant with amino groups and aromatic moieties were tested as adsorbents for an anionic dye such as Congo Red, and their absorption capacity towards dye was found to be ca. 500 mg/g. Beside demonstrated here application of PET-derived hydrogels for water cleaning from an industrial dye, utilization of such hydrogel materials in fields of environment, agriculture, separation, etc. are also anticipated.