COMPARATIVE-STUDY ON MILD DEPOLYMERIZATION OF LIGNIN MODEL DEHYDROGENATION POLYMERS AND MILLED FOOD LIGNIN

Dehydrogenation polymers (DHPs) of coniferyl alcohol prepared in three different ways (bulk, end-wise and membrane) and spruce (Picea marian a) milled wood lignin (MWL) were depolymerized with dry hydrogen iodid e. The amounts of the only monomeric product, 1, 3-diiodo-1-(4-hydroxy -3-methoxyphenyl)propane and oligomeric products resulted from this pr ocedure were compared. All DHPs differ noticeably from MWL in their st ructural organization, the bulk one being the best approximation. Yiel ds of the diiodide were high in all cases (end-wise DHP: 45%, membrane DHP: 55%, MWL and bulk DHP: 20%). Molecular mass distributions of hig her molecular mass products were similar in all the cases except end-w ise DHP which demonstrated lesser degree of polymerization of high mol ecular mass fraction.