Topological Structure of Lignin Macromolecules

According to Erins [8, 9], the spatial structure of amorphous lignocarbohydrate matrix of wood is described by a superposition of three networks a network of hydrogen bonds (H -network), which involves both lignin and carbohydrates a network of lignocarbohydrate valence bonds (LCV network), and a lignin network. 

The concept of treating native lignin as a network structure has become popular, because this model makes interpretation easier of the complex processes that occur during the technological treatment of wood. The strongest argument in favour of the network model 

Using the theory of branching processes, the condition for gelation was verified and the mean molecular mass of the sol fraction was calculated. It was demonstrated that all theoretical lignin models (except for models of lignosulfonate from spruce) satisfy Flory s critical condition for gelation, which, in terms of the theory of branching processes, is defined by the inequality  

Heterogeneity with respect to the molecular structure [20,21]. One may assume that topological heterogeneity is predetermined genetically by the microstructure of chains. 

An increase in probability of cyclisation as the molecular mass of macromolecule increases [22]. This factor follows from general considerations about the feasibility of intramolecular interaction between functional end groups during the growth of a branching tree [12]. 

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