engleski

Carbamide-formaldehyde adhesive systems modified with liquefied wood Part I. Acid catalyst method of wood liquefaction with various polyhydric alcohols

Wood liquefaction of black poplar (Populus nigra L.) with various polyhidric alcohols through acid catalyst method was studied for the purposes of determination the best polymer characteristics of liquefied wood, as a further raw material in modified carbamide-formaldehyde resin synthesis, with respect to adhesives in wood based panels production. For liquefaction we used several types of polyhidric alcohols (PEG, DEG, DPG, EG and glycerol) and H2SO4 as acid catalyst under defined conditions of liquefaction reaction: wood/liquefaction reagent/H2SO4 = 20.00/112.45/3.37 gram, at 150 °C for 120 min. For various liquefaction reagents mixtures of polyhidric alcohols, undissolved residue percentage (0.50-5.69%), and hydroxyl OH-number (88-567 mg KOH/g) was provide as a value which determine liquefied wood polymer characteristics. The best effects were achived using mixtures of glycerol/DEG/H2SO4 (80/20/3) and glycerol/ H2SO4 (100/3).

liquefied wood; polyhydric alcohols; acid catalyst; undissolved residue; hydroxyl number

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