Assertion: lignin's group | /r/HasAspect | pk
Facets:
Source sentences:
text: As the pK a values of the carboxylic acid groups of lignin are below 4.6 and most of the pK a values of the phenolic groups lie above 9 (with some species with electron-withdrawing groups having a pK a value between 7.3 and 9), it can be observed that there is almost no overlap between the deprotonation of carboxylic acid and phenolic groups of lignin.31P NMR.