PREPARATION OF POLYURETHANE FROM LIGNIN AND CRUDE GLYCEROL

摘要

Polyurethane foam (PUF) was prepared by a novel approach, using a renewable polyol derived fromrnonly biofuel production by-products, lignin and crude glycerol. This could potentially be a high value bio-refineryrnapplication for the two byproducts from cellulosic ethanol and biodiesel production, respectively.Renewable polyolsrnwere synthesized by the liquefaction of lignin in crude glycerol.Three different technical lignins were individuallyrnemployed to preparepolyols viz.: kraft lignin, lignosulfonates and organosolv lignin.Water-blown polyurethane (PU)rnfoam was prepared by reacting the polyols with commercial diphenylmethane-4,4'-diisocyanate (MDI). The PUF hadrncompressive strength which conform to industry requirements for thermal insulation [1]. The PUF had renewablerncontent as high as 44 wt%.A major benefit of these renewable polyols is that PUF could be prepared without the needrnto add any petroleum derived polyols. Making use of lignin instead of untreated agricultural residues i.e.rnlignocellulose, enables the production of both biopolyols and cellulosic ethanol.The structural differences of technicalrnlignins clearly have a significant influence on the ensuing PU properties. Biomass pretreatmentmethods and speciesrntherefore need to be selected with consideration to their effect on lignin properties if the high lignin content present inrnmany biomass types are to be exploited.