马占相思树皮磷酸催化液化及其液化物树脂化的研究

Phosphoric Acid Catalyzed Liquefaction of Acacia mangium Bark and Resinification of Liquefied Products

以苯酚作液化剂、磷酸作催化剂对马占相思树皮进行液化研究,分析了液化温度、催化剂用量、液化时间及液固比对液化反应的影响;通过正交实验得到马占相思树皮磷酸催化液化的最优方案,并研究树脂化过程的影响因素和工艺。结果表明:(1)随着液化温度升高、磷酸用量增加、液化时间延长和液固比的增加,马占相思树皮液化物的残渣率均呈明显的下降趋势;(2)马占相思树皮磷酸催化液化程度对液化温度的变化更敏感。最佳液化工艺条件为:液化温度170℃,催化剂磷酸加入量为9%,液化时间2.5 h,液固比4.5:1,残渣率为20.1%;(3)液化产物树脂化合成表明,甲醛与液化产物摩尔比、反应温度及保温时间对液化产物树脂的粘度有显著影响。对树脂的胶合性能进行测试,结果表明,以其压制的3层胶合板强度符合国家标准中对Ⅰ类胶合板的胶合强度要求(≥0.7MPa)。

Using phenol as liquefier, and catalyzed by phosphoric acid, factors influencing the liquefaction of Acacia mangiurn willd bark were investigated, such as temperature, amount of catalyst, time, and ratio of solvent to solid material. The optimal conditions were obtained by orthogonal experiment, and factors influencing the resinification of liquefied products were also studied. The results showed that： （1） the proportion of solid residue decreased significantly with the increase of temperature, amount of phosphoric acid, and liquificaion time; （2） orthogonal experiment indicated that the principal factor during was temperature, the optimal conditions were as follows： temperature： 170℃, amount of catalyst： 9%, time of liquification： 2.5 hours, ratio of phenol to the bark： 4. 5 ： 1, the residues rate： 20. 1% ; （3） the resinification of liquefied products, indicated that the molar ratio of formaldehyde to liquefied products, reaction temperature and holding time had significant impacts on the viscosity of phenol-formaldehyde resin, the characters of liquefied products resin can meet the standards of GB/T 17657-1999 4.15 for wood industry.