【作者】 高雨；

【导师】 陈学榕；

【作者基本信息】 福建农林大学 ， 木材科学与技术， 2006， 硕士

【摘要】 为了保护自然生态环境，减少木材的耗量，目前造纸工业广泛利用二次纤维及草类植物纤维制浆造纸，但由于这些纤维本身的特性，都存在成纸强度差、纸质低等缺陷，已经成为目前制浆造纸行业亟需解决的问题。制浆造纸工业多年生产实践经验证明：纸浆中添加适量的增强剂是解决纸页强度的一种有效的途径。 在化学法制浆中产生的黑液，其中的固形物占整个造纸工业污染的90％，是主要的污染源，且主要采用燃烧法碱回收黑液处理工艺，有机物作为燃料回收，其利用价值不高。因此，无论从资源有效利用还是从解决环境污染问题的角度考虑，研究利用碱木素已经成为有较大经济价值和深远社会意义的课题。 本课题研究和探讨了改性木素、改性木素-脲醛树脂合成物、改性木素-三聚氰胺甲醛树脂的制备、增强效果及合成与增强机理。 碱木素基本结构单元分子类似于苯酚，含有酚羟基，醇羟基，甲氧基等活性基团，可以发生羟甲基化等改性反应。木素经过改性后，使之与UF，MF等增强作用树脂进行共聚，然后添加到纸浆中并留着，使之与纤维形成交联，则起到提高纸页或者纸板强度的效果。 根据木素结构特征，用甲醛对碱木素进行羟甲基化，反应产物改性木素与脲醛树脂、三聚氰胺甲醛树脂合成增强剂（ML-UF、ML-MF），并优化出各个反应的最佳反应条件：①碱木素羟甲基化改性：甲醛用量6.33mmol·g^-1lignin，pH值10.5，反应温度65℃，反应时间90min；②合成ML-UF：ML用量40％，pH值8.5，反应温度45℃，反应时间3.5h；③合成ML-MF：ML用量80％，pH值8.5，反应温度45℃，反应时间3.0h。 三种改性产品应用试验表明：控制纸浆pH值为4.5～5.5，增强剂用量为6％时，纸页抗张强度最大，可分别提高纸页的干强度为33.8％、59.1％、63.4％，而且纸页润湿后，其湿强度保持为干强度的40.2％、38.8％、42.5％。 红外光谱研究表明：改性木素结构基本保留原有木素的基团特征吸收，并且明显的增加了1060cm^-1羟甲基的C—O振动吸收，证实碱木素己羟甲基化；同时通过ML-UF、ML-MF样品的红外光谱的研究，证实了改性木素与脲醛树脂、三聚氰胺甲醛树脂已经进行了交联。 纸页扫描电镜观察研究证实：添加了ML、ML-UF与ML-MF的纸页，其平面上出现的孔洞数目大量减少，而且还出现较多纤维之间的桥连，可以推测，加入增强剂能增加纤维之间的结合力。 纸页热分析研究表明：TG图中，添加增强剂的纸页失重量大于未加助剂的纸页，而且各自的失重温度范围不同，可见两种纸页的挥发成分的耐热性不同；在DSC图中，加入增强剂的纸页的构象变化所需的能量大于空白样，说明增强剂的加入提高了纸张的热稳定性。 碱木素改性制纸页增强剂可有效提高纸页的强度，具有原料来源广，生产成本低，为制浆造纸黑液的合理利用提供有效途径。更多还原

【Abstract】 Now secondary fibers and herbs fibers are broadly used for pulp and paper in paper industry for protecting the environment and reducing the lumber dosage. However, because of those fibers’ characteristics, it has been become a burning problem that the paper product made from those fibers has a defect of bad strength and low quality. As is well known, adding reinforcing agent to pulp properly is an effective way to deal with paper strength.The black liquor from chemical pulping industry, in which the solid has 90 percent of the paper industry pollution, is the main pollution source. Now it mainly takes burning way to reclaim alkali wastes, but the value of organic matter as forward recovery is not high as recovery. So the research on alkali lignin enjoys large economic and social value.The paper has researched and discussed the preparation, strengthening effect, composing and strengthening mechanisms of 3 resins, which are modified lignin (ML), modified lignin-beetle (ML-UF) and modified lignin-melamine formaldehyde resin (ML-MF).The basic structural motive of alkali lignin is similar with phenol, containing phenol-carbonyl, alcohol-carbonyl, metonym and other active groups, and it can set off a reaction of carbonyl modification. By modification, modified lignin can react with UF and MF, which have function of strengthening effect, then the product are added to pulp. In pulp, this product can make a structure with fiber and strengthen the strength among fiber, therefore, the strength of paper or paper boxes can be improved.Based on lignin’ s structure characteristics, alkali lignin is modified by formaldehyde, then modified lignin is composed of ML-UF, ML-MF with beetle(UF) and melamine formaldehyde resin(MF) and the best conditions of these three reactions are optimized, as follows:①Lignin modification: formaldehyde dosage 6.33 milli-mol per gram lignin, potential of hydrogen(pH) 10.5, reactive temperature 65℃, reactive time 90 minutes;②ML-UF reaction: ML dosage 40%, pH 8.5, reactive temperature 45℃, reactive time 3.5 hours; ③ML-MF reaction: ML dosage 80%, pH 8.5, reactive temperature 45℃, reactive time 3.0 hours.It is shown from applicative experiments of three modified product (ML, ML-UF, ML-MF) : When the variables of pH, reinforcing agent are 4.5 to 5.5,6%, respectively, paper strength is the best, and the added values of paper dry strength are更多还原