A Comparative Analysis of Wax and Solid Residues From Plastic Wastes Pyrolysis by FTIR Spectroscopy

Following the division of the PET-1 plastic samples (Azerbaijan-made, SIRAB brand noncarbonated beverage) used for the study into 1 cm² pieces, they were fired in quartz ampoules at temperatures of 350°C, 450°C, and 550°C for one hour. The FTIR spectroscopy method was applied in accordance with the objectives of the study. Since PET is thermally stable, separation of the volatiles occurs above 420°C. At 450°C, peaks characteristic of wax are observed in the wavenumber range of 2500–3062 cm ^− 1 , which may be due to the dispersion of the ether group in the PET macromolecule (these peaks are absent in the original sample). In our study, we observed a peak at approximately 1679 cm ^− 1 , which we believe may be characteristic of the ether (C = O) group. During the thermal destruction of the PET-1 samples at temperatures of 450 and 550°C, strong peaks appear in the regions of 1260, 1085, and 1020 cm-1 in the FT-IR spectra, which could be indicative of the presence of carboxylic acids.