Fig. 3: Decolorization of dark TPA.
From: Acetolysis of waste polyethylene terephthalate for upcycling and life-cycle assessment study
a Dark TPA obtained directly from acetolysis of Variegated clothes. b Product obtained by decolorizing dark TPA (sample a) in an alkaline solution with activated carbon. c Product obtained by decolorizing dark TPA (sample a) in N, N-dimethylacetamide with activated carbon. d Product obtained by decolorizing dark TPA (sample a) in hot water (280 °C) with activated carbon. The yield of decolorization (purity after decolorization) is shown in the figure, and the chromaticity after decolorization is all 5 Hazen. e XRD pattern of dark TPA (sample a). f XRD pattern of TPA decolorized with an alkaline solution. g XRD pattern of TPA decolorized with N, N-dimethylacetamide. h, XRD pattern of TPA decolorized with hot water. i SEM image of dark TPA. j SEM image of TPA decolorized with an alkaline solution. k SEM image of TPA decolorized with N, N-dimethylacetamide. l SEM image of TPA decolorized with hot water. All dark products obtained by acetolysis of waste PET material were easily decolorized in the described ways, including colored plastic bottles and black trays.
