POLYURETHANES BASED ON OXYGEN-ORGANOSOLV LIGNIN

Oxygen-organosolv lignins, isolated from spent liquors after delignifi cation of wood in different acidic organic solvent-water media, were u sed as unmodified macromonomers in conjunction with an oligoethyleneox ide di-isocyanate. This led to crosslinked elastomeric polyurethanes w hich were thoroughly characterized. It was found that the nature of th e organic solvent used for the organosolv pulping had an influence on the reactivity of the isolated lignins towards the di-isocyanate becau se of the variation in the amount of alcoholic groups caused by reacti ons with solvent molecules during the delignification. (C) 1998 Elsevi er Science Ltd. All rights reserved.