Depolymerization of poly(ethylene terephthalate) waste

Abstract

Poly(ethylene terephthalate) waste was depolymerized with ethylene glycol in the presence of different catalysts, two conventional metal catalysts (zinc acetate and lead acetate) and two alkalies (sodium carbonate and sodium bicarbonate). The resulting monomer bis(2-hydroxy ethylene terephthalate) was characterized by thin layer chromatography, melting point, IR spectroscopy, differential scanning calorimetry, and elemental analysis. The results show that the qualitative and quantitative yields of the monomer obtained with alkalies as catalysts were most comparable with the conventional heavy metal catalysts, thus providing a further advantage for the recycling of polyester waste for the cause of environmental pollution abatement.

Recent Developments in the Chemical Recycling of PET

“…They started with mild alkalies, sodium carbonate and sodium bicarbonate, and reported that the monomer yields (Refer to Table 2) were comparable with those of the conventional zinc and lead acetate catalysts (Shukla & Kulkarni, 2002). They also reported glacial acetic acid, lithium hydroxide, sodium sulfate, and potassium sulfate to have comparable yields (Table 2) with those of the conventional heavy metal catalysts (Shukla & Harad, 2005).…”

Poly (ethylene terephthalate) recycling for high value added textiles

“…The glycolysis rate and BHET monomer yield are dependent on various reaction parameters such as temperature, PET/ethylene glycol ratio, and type and amount of catalysts. A number of studies are summarized in Table 3, detailing the optimum glycolysis conditions and reaction parameters obtained (Dulio et al 1995;Pingale et al 2010;Xi et al 2005;Troev et al 2003;Shukla and Kulkarni 2002;Shukla et al 2008;Imran et al 2011;Wang et al 2009;Yue et al 2011). …”

Degraded Pet for the Removal of Metal Ions From Aqueous Solution

“…Chemical degradation of PET produces low molecular weight compounds with functional groups taken from the nucleophilic agent used in the chemical process, for example, hydroxyl group in glycolysis or amine group in aminolysis 14 . These degradation products have been used as precursors of new products such as fatty amide derivate in textile processes 15 , unsaturated polyester resins 16 , epoxy resin hardeners 17 , and polyurethanes 18 .…”