LIQUEFACTION OF WOOD IN THE PRESENCE OF POLYOL USING NAOH AS A CATALYST AND ITS APPLICATION TO POLYURETHANE FOAMS

The influences of various reaction parameters (e.g. temperature, time, type and concentration of polyol, and swelling agent) on the extent o f liquefaction of the wood meal in polyol, and the properties of the l iquefied wood-polyol mixtures have been evaluated. The residue % decre ases significantly with the increase of reaction temperature. Similarl y, residue Sb decreases with the increase in reaction time up to 1 h, and also with the increase in NaOH concentration from 0% to 2.5%. More over, a polyol:wood weight ratio of 4:6 offers lowest residue. ?he eff ects of various formulations for the preparation of polyurethane foams from the concentrated liquefied wood-polyol mixtures on the density, compressive strength and modulus of the resulting foams have also been evaluated. Both molecular weight and concentration of the polyols hav e profound influence on the residue %, acid and hydroxy values, and mo lecular weight of the liquefied wood-polyol mixtures as well as ultima te properties of the urethane foams. Once again, with the increase in concentration of blowing agent, e.g. water, both density and modulus o f the foams increase, while compressive strength decreases. On the oth er hand, with the increase in isocyanate index both density and modulu s decrease, but compressive strength increases.