fig11
Figure 11. Chemical State Profiling of the Char Surface. High-resolution XPS spectra acquired from the TPU/APP-3BL composite residue: (A) Ti 2p, (B) Si 2p, (C) P 2p, (D) N 1s, (E) C 1s, and (F) O 1s. TPU: Thermoplastic polyurethane; XPS: X-ray photoelectron spectroscopy; APP: ammonium polyphosphate.
