Chemical recycling versus enzymatic degradation of polyethylene terephthalate pre-treated via an ultrafast dissolution-reprecipitation approach. Olivia Attallah 1 , Olivia Soliman 1 , George Taxeidis 2 , Evangelos Topakas 2 and Margaret Brennan Fournet 1 1 Materials Research Institute, Technological University of the Shannon: Midlands Midwest, Athlone N37 HD68, Ireland. 2 Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece Polyethylene terephthalate (PET) is one of the most common plastic types used in packaging industry. PET plastic waste pretreatment has been proposed as one of the techniques to enhance the efficiency of PET degradation while using milder depolymerization conditions. In this context, we introduced a novel, ultrafast pretreatment based on a dissolution/reprecipitation approach under microwave (MW) irradiation. Differential scanning colorimetry (DSC) and Fourier transform infra-red (FTIR) analyses of the pretreated PET plastic waste indicated a significant decrease in crystallinity index and an increase in the carbonyl index than the untreated sample. Efficiency of degradation of both untreated and pretreated PET plastic waste was evaluated using enzymatic degradation and MW assisted chemical depolymerization techniques. Results elaborated that the pretreated PET conversion rate and the terephthalic acid (TPA) monomer yield post the MW assisted hydrolytic depolymerization was significantly higher than that of untreated sample and enzymatic degradation recording a 95% PET conversion and 87.4% TPA yield. It is also worth mentioning that the proposed pretreatment approach did not show a significant effect on PET enzymatic degradation. Nevertheless, it resulted in a slight improvement in the enzymatic conversion of PET into monohydroxyethyl terephthalate (MHET) which was then converted into TPA.
P250-L
© The Author(s), 2023
Made with FlippingBook Learn more on our blog