【作者】 刘春雨；

【导师】 张求慧；

【作者基本信息】 北京林业大学 ， 木材科学与技术， 2010， 硕士

【摘要】 为了更好利用废弃白蜡(Fraxinus Chinensis Roxb)枝桠材,降低常规酚醛树脂的制造成本,降低对石油资源的依赖,本论文以白蜡枝桠材为原料,在苯酚与四氢萘混合溶剂中经浓硫酸催化得到其液化物,通过正交试验得到优化液化工艺；较系统地研究了液化物树脂合成工艺,也通过正交试验得到优化树脂工艺；探讨不同热压工艺参数对白蜡枝桠材混合溶剂液化物树脂胶合性能的影响,并通过正交试验获得其优化热压工艺；借助SEM、FTIR等手段初步分析了木材液化及树脂化的基团变化和反应历程。1.液化的优化工艺为：反应温度为150℃、时间为2.5h、木酚比为1：6、催化剂H2SO4用量为6.5%、四氢萘用量为20%,在此工艺条件下,液化效率可以达到96%左右。且时间对液化效果的影响最为显著,其次为温度、再者为木酚比和催化剂用量,对液化效果影响最小的因素为四氢萘用量。2.在树脂化过程中时间越长、温度越高、甲醛用量越多、所生成的白蜡枝桠材混合溶剂液化产物的树脂粘度越高,随着碱加入量的提高,白蜡枝桠材混合溶剂液化产物的树脂粘度有一个先增加后降低的过程。白蜡木枝桠材混合溶剂液化产物的树脂化优化工艺条件：树脂化温度为82℃,甲醛/木材液化物摩尔比为1.9，氢氧化钠/木材液化物摩尔比为0.3,时间为140min。时间对树脂粘度影响最大,其次是树脂化温度,氢氧化钠/木材液化物摩尔比和甲醛/木材液化物摩尔比。3.热压工艺优化参数为：热压温度为165℃、热压压力为1.4MPa、时间为6min、涂胶量为290 g/m2。随着热压温度的增加胶合板的胶合强度是先增加后减小的过程；随着热压时间的增加胶合强度是先快速增加后减小的过程；随着热压压力的增加胶合强度是先增加后减小的过程；随着涂胶量的增加胶合强度是先降低后增加的过程,但是总体上随着涂胶量的增加胶合强度也不断增加。压制的三层杨木胶合板胶合强度达到Ⅰ类胶合板要求。4.据FTIR的分析表明液化反应中木材组分发生了明显酚化反应,酸性条件下纤维素的晶格结构遭到破坏,半纤维素被降解,木素液化降解成低分子物质；白蜡枝桠材混合溶剂液化物树脂FTIR谱图具有典型酚醛树脂的特征吸收峰。更多还原

【Abstract】 In order to reuse the branch of wood, the branch of Fraxinus chinensis Roxb was liquefied in the Petralin-Tetralin mixed Hydrogen-Donor solvent. We carry out the research, untilizing the orthogonal. we have obtained optimum liquefaction processing parameters、resin processing parameters and hot-press processing parameters. Changes of groups and mechanism of reaction were analysed by FTIR and SEM; The result is as follows:1)The reaction conditions are temperature of 150℃,the reaction time of 2.5h,liquid radio(pHonel/wood weight ratio) of 6, Tetralin content of 20% and catalyst content of 6.5%,.4% residue could be reached. the reaction time plays the most important role in all factors, followed by reaction temperature, liquid ratio,catalyst content and tetralin content. the more we pick out the liquefaction processing parameters, except catalyst content, the less residue ratio can be reached. The best effect manufacturing the liquefied wood is the time which human spend in the whole process.2) The reaction best temperature, making the proper resin, is 82℃,. and the best time is 140min. As the same time, the NaOH/liquefied wood molar ratio is 0.3, and the pHonel/liquefied wood molar ratio is 1.9.3) we want to get the best bond strength of plywood, the hot-press processing parameters is that the temperature is 165℃, and the pressure is 1.4MP,and the time is 6min. Finally you need to paint 290 g/m-2 resin in the board. The best bond strength is 1.77MPa.4) Analyzing paints of FTIR of liquefied wood resin, which was similar to the traditional PF resin of the chemistry character. crystal lattice of crystal was destroyed; hemicelluloses ans lignin were deteriorated to the low molecule. Studying the picture of the SEM about the liquefied wood resin and the traditional PF resin, we find the traditional PF have the more fine substance.更多还原