Also called wood lignin,An aromatic polymer compound found in plant fibers.
It has the function of strengthening cell wall and binding fibers in plant tissues. Its composition and properties are relatively complicated, and it has extremely strong activity.
It cannot be digested by animals and can be transformed into humus in the soil. If lignin is simply defined, it can be considered as an enzyme dehydrogenation polymer of p-hydroxycinnamyl alcohols. It contains a certain amount of methoxy groups and has certain characteristic reactions. Lignin is a major component of plant cell walls. According to the amount of lignin contained in the pulp, chemical pulp can be about 15%, and mechanical wood pulp contains almost all.
It is also used to prepare vanillin and dimethyl sulfoxide. It can also be used as a tanning agent or adhesive. Dissolve plant fibers with concentrated acid and extract lignin with alkali. The former was dissolved in 72% sulfuric acid. After extraction with organic solvents, lignin precipitated.
The latter treats the sample with a caustic soda solution at a high temperature of 170-180 ° C, extracts lignin, and acidifies it in the extract to precipitate and separate. Chemical or synthetic resin can be reacted to obtain the corresponding lignin resin.