Table 5.

³¹P NMR analysis of DES-Lignin.

Chemical Shift (ppm)	Assignment	Content (mmol·g−1)
133.8–135.0	Carboxyl	0.182
137.0–138.4	p-phenol hydroxyl (H)	0.110
138.4–140.2	Guaiacyl phenol hydroxyl (G)	0.285
142.4–143.7	Syringyl phenol hydroxyl (S)	0.520
-	G:H:S	2.59:1:4.73
140.2–142.4, 143.7–144.4	Condensation phenol hydroxyl	0.539
145.2–150.1	Aliphatic hydroxyl	0.606
-	Total phenol hydroxyl	0.915
-	Total hydroxyl	2.06