“…[38] The peak at 2.17 and 2.24 ppm corresponds to the methylene group adjacent to the alkyne (-C≡) group and carboxylic group respectively. [38] In the case of PCE, following the functionalization of PC with EGME, three additional peaks appeared at 3.49, 3.35, and 4.23 ppm, which were assigned to methylene groups adjacent to the oxygen of the carboxylic and methoxy groups, respectively. Conversely, in PCD, as the number of ethyleneoxy units increased, peaks appeared at 4.24, 3.56, and 4.18 ppm, corresponding to methylene and methoxy groups, respectively.…”