Fig. 2: Morphological and structural features of paper plastic.

a Schematic of polymer (NIPU) preparation. b FTIR spectra of CSBO, APAC, PEI, and NIPU. c SEM images of cellulose paper and paper plastic. Scale bar, 50 μm. d One-dimensional Raman spectra and two-dimensional (2D) Raman spectra constructed from the intensity of C=O. e FTIR spectra of paper and paper plastic. Source data are provided as a Source Data file.