Self-crosslinking and film formation ability of liquefied black poplar.

Black poplar wood, diethylene glycol (DEG), and sulphuric acid as a catalyst were used as starting reactants for liquefaction. Optimal conditions for liquefaction were established: reaction temperature 150 degrees C, reaction time 95min, ratio of wood:DEG=1:5 and 3% of sulphuric acid addition. The liquid mixture obtained by the liquefaction was composed of the real product of the reaction (the so called "excess solvent free liquefied wood" (ESFLW)) and of the remaining unreacted DEG.