Study of the reactivity of Kraft and organosolv lignins with 4, 4’–diphenylmethane diisocyanate and characterization of the obtained products

The interaction of two types of lignins: Kraft lignin (KL), isolated according to the LignoBoost process (Sweden), and Alcell organosolv (OL) lignin (Canada), with 4,4’-diphenylmethane diisocyanate (MDI) in the dry dioxane media at 25 degrees of Celsius, was investigated. In the presence of dibutiltin dilaurate (DBTD) the second order rate reaction and 43-56 % conversion were observed. After that the negative deviation from the second order kinetic was observed. The complete NCO conversion in the case of KL takes more time than that of OL