Lignin is also known as wood or lignin. A complex aromatic polymer compound found in plant fibers. It varies with the source of the lignin and the method of isolation and purification. The color of isolated lignin ranges from light cream to dark brown. It is not optically active. Refractive index 1.61. density 1.25 to 1.40 g/cm2. Molecular weight is several hundred to several hundred thousand, with polydispersity. The molecular weight of wood lignin is 10,000-20,000, and that of Gramineae lignin is 7,000-9,000; the molecular shape of the molecule is close to globular or lumpy. It is insoluble in common neutral organic reagents. Lignin has thermoplasticity, and its softening temperature is related to the molecular weight and water content of lignin. The softening temperature of dry separated lignin is generally 120～200℃. The thermoplasticity of lignin is closely related to the pulp and paper and wood processing industries.
Sulfate Lignin can be involved for making moisture-resistant paper.
Primary dispersing agent for dyestuffs and agricultural chemicals.
Lignin, alkali can be used as a surface treatment agent for composites of natural fibers with petroleum based resins. It can be used as a biosorbent for potential applications in removing toxic metal ions from wastewater.
Lignin, alkali is a complex, three dimensional polymer that is also known as kraft lignin that has undergone hydrolytic degradation. It is one of the major components of lignocellulosic materials. Lignin is a major product for second generation bioethanol production and is an impurity in the separation of cellulose from wood.
