In this study, we present an analytical method utilizing thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA–FTIR) to accurately identify and quantify components in both single biodegradable and composite polymer systems. With increasing use of biodegradable plastics and their composites (PCL/TPS, PBAT/TPS, PLA/PHA), precise compositional analysis is essential for recycling and circular resource applications. However, conventional methods such as Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS), nuclear magnetic resonance (NMR), and solvent extraction remain limited for multi-component systems. Here, we demonstrate that TGA–FTIR enables simultaneous, real-time qualitative and quantitative analysis of each component in both single and composite polymers. Calibration curves showed excellent linearity (r 2 ≥ 0.99), and interlaboratory comparisons confirmed no significant differences, validating the robustness of the method. This approach provides a reliable protocol for compositional analysis and quality verification of biodegradable polymer blends. • A real-time TGA–FTIR method for qualitative and quantitative polymer analysis • Optimized calibration achieves high quantification accuracy with r2 ≥ 0.99 • Validated for ten polymers and blends including PCL/TPS, PBAT/TPS, and PLA/PHA • The protocol supports recycling feedstock assessment of complex polymer composites
Choi et al. (Fri,) studied this question.