New recycled polyethylene terephthalate imidazolium ionic liquids and their applications for co₂ exhaust capture

The recycling of polyethylene terephthalate (PET) waste using imidazolium ionic liquids IILs to capture CO₂ exhaust offers a sustainable and environmentally friendly approach to addressing the challenges of plastic waste pollution. The functionalized imidazolium acetate with two hydroxyl and amine end groups were prepared by simple method for glycolysis and amidolysis PET to produce water soluble oligomers during short reaction time at 180 °C. ¹HNMR analysis was used to determine the functionality and molecular weight of recycled PET oligomers with 1,3-bis(2-hydroxyethyl)-1H-imidazol-3-ium acetate ionic liquid (HIIL) and 1,3-bis(3-aminopropyl)-1H-imidazol-3-ium acetate ionic liquid (HIIL) AIIL that were 3565.7 and 1316.23 g.mol^-1, respectively. The thermal stability and characteristics prove that the formation of elastic oligomers having higher elasticity for RPET-HIIL > RPET-AIIL that have T_g values for RPET-HIIL and RPET-AIIL at -69.34 and -48.44 °C, respectively with disappearance of T_g of PET. The CO₂ absorption capacities at atmospheric pressure confirm that RPET-AIIL and RPET-HIIL absorb more CO₂ with higher efficiency to about 25.2 mol CO₂/ Kg _IIL and desorbs CO₂ more easily in the short time.