Andrej Kržan,*a
Matjaž Kunaver,a and Vesna Tišlerb
a National Institute of Chemistry, Laboratory for Polymer Chemistry and Technology,
Hajdrihova 19, POB 660, 1001 Ljubljana, Slovenia, E-mail:
andrej.krzan@ki.si
bUniversity of Ljubljana, Biotechnical Faculty, Department of Wood Scince and
Technology, Rožna dolina C VIII/34, POB 2995, 1001 Ljubljana, Slovenia
Abstract
Liquefaction of Central European hardwoods was
performed using a number of different glycols in combination with dibasic
organic acids and a minor addition of ortho-phosphoric acid as a catalyst. The
reaction carried out at 190 °C resulted in liquefaction of 15–56% of the
original wood. The best effects were achieved using propylene glycol as the
solvolytic reagent and maleic anhydride as the the acidic reagent. The
unsolubilized solid remains were investigated using scanning electron microscopy.
The liquefaction product examined by size exclusion chromatography and infrared
spectroscopy was composed of low molar mass oligomeric polyesters.
Key words: renewable resources, liquid wood, wood dissolution, waste wood, polyester