Primary Studies On The Alcoholysis Of Triploid Clone Of Populus Tomentossa Carr. With Ethylene Glycol

Liquefaction of wood in the presence of phenol or polyhydric alcohols is a new technique, which is a novel process to effectively convert chemical components of wood into a polymer with high additional values. The experiments of triploid clone of populus tomentossa carr. liquefied in the presence of ethylene glycol under sulfuric acid catalysis were conducted. The factors influencing wood liquefaction were analyzed and the optimum liquefaction processing parameters were defined. Based on the structure analysis of the liquefied MWL, the reaction of MWL in the liquefaction process of the triploid clone of populus tomentossa carr. was studied. The liquefied products and liquefaction process of the triploid clone of populus tomentossa carr. were analyzed by using FTIR and XRD. And FTIR, GPC and ~1H-NMR were used to analyze the structure, molecular weight and reaction of MWL and its liquefaction products. The lignin in liquefied liquor of the triploid clone of populus tomentossa carr. with ethylene glycol was also analyzed by FTIR. The following results are obtained.1. Though changing the affected factors of reaction time, holding temperature and catalyst consumption, the optimum condition of alcoholysis for the triploid clone of populus tomentossa carr. is: 180℃, 100min, liquid ratio 1:6 and catalyst content 1-2% while the liquefaction ratio is the best.2. In the alcoholysis process, the triploid clone of populus tomentossa carr. dissolved in ethylene glycol and the residue content became less and less. The wood structure was destroyed and the crystallinity of residues reduced. With the reaction conditions changing severe, the wood structure was destroyed more and more heavily. The wood was dissolved more thoroughly.3. The MWL of the triploid clone of populus tomentossa carr. is typical hardwood lignin. Under high temperature and acid catalysis, it was easily liquefied and the structure changed. Conjungate carbonyl group diappeared and the amount of unconjungated carbonyl raised. The amount of phenolic hydroxyl group and alkylene increased, which is more benefit for lignin liquefaction products to be modified. Relative molecular mass distribution became broader as the reaction was prolonged, indicating condensation occurred simultaneously with degradation of lignin.