Fig. 9

ATR FT-IR spectra of the solid (cotton) residue after PET hydrolysis. In a, a comparison between a sample where only 66% of the TPA yield had been reached (5% NaOH, 70 °C, 240 min) and a sample where full yield had been reached (10% NaOH, 90 °C, 240 min) is shown. Both from large-scale experiments, 52 mmol BTBAC/kg solution. In b, a comparison between pure cotton sheets (as a reference), a sample treated in 15% NaOH (90 °C, 100 min, small-scale experiments, 52 mmol BTBAC/kg solution), and a sample treated in 10% NaOH (90 °C, 240 min, large-scale experiments, 52 mmol BTBAC/kg solution) are shown