Table 1.

Quantification of the functional groups (mmol/g) in the lignins of PAL and PPAL using a quantitative 31P-NMR method.

δ(ppm)	Assignment	PAL (mmol/g)	PPAL (mmol/g)
145–148	Aliphatic OH	0.072	0.139
141.5–143	Syringyl OH	0.368	0.056
138.5–139.5	Guaiacyl OH	0.180	0.060
137–137.9	p-Hydroxy phenyl OH	0.012	0.369
133.4–135	Carboxylic OH	0.024	0.004
	Active sitesa	0.192	0.429

^aThe amount of active sites available for the subsequent graft polymerization; Active sites = Guaiacyl OH + p-Hydroxy phenyl OH.