Direct action of molecular ozone against lignin and its standard compounds.

The accurate formulation of lignin macromolecular structure is a complex re search field due to the difficulty to isolate representative lignin samples and to their trend to undergo autocondensation reactions, many of them of unknown nature. One of the possible ways to study the lignin structure is i ts oxidation with oxone to produce low molecular weight compounds. The appl ication of low ozone rates results in the rupture of intermonomer bonds and the formation of aromatic compounds. On the other hand, the application of high ozone rates results in the appearance of oxidated forms of the side c hains which link the different phenylpropane units. The structural elucidat ion of aromatic compounds and oxidated side chains gives information about the type of phenylpropane units existing in lignine and about the type of l ink between them.