【作者】 曾丽萍；

【导师】 周小凡；

【作者基本信息】 南京林业大学 ， 制浆造纸工程， 2004， 硕士

【摘要】 现代造纸工业正在向着中一碱性、白水高度封闭循环的方向发展，阴离子垃圾在循环使用的白水中不断累积，对湿部各种添加剂(特别是阳离子型添加剂)均造成了不同程度的影响：增加了它们的消耗量，使造纸成本不断上升。目前已研制出一种较好的非离子型助留助滤体系，它是由聚氧化乙烯(Polyethylene oxide，简称PEO)及膨润土(bentonite)组成的微粒助留体系；研究结果表明它具有较好的抗阴离子杂质干扰的性能。本研究在这个助留体系的基础上，探讨了传统阳离子AKD施胶剂在新型助留体系和阳离子聚丙烯酰胺(CPAM)／膨润土助留体系中的应用效果，同时测定其在阴离子杂质存在情况下的施胶效果，并添加酚醛树脂改善在新型助留体系中的施胶度；另外通过对AKD的乳化剂配方和乳化工艺进行改进，制备出一种能抵抗阴离子杂质干扰的新型AKD乳液，并对其应用效果和留着机理进行了探讨。主要研究结果如下： (1)在PEO／膨润土和CPAM／膨润土体系中，阳离子AKD乳液能取得较高的施胶度；但是阴离子杂质的存在对传统阳离子AKD乳液的施胶效果均有较大影响，施胶度下降幅度平均约为30％；添加酚醛树脂可以一定程度上改善阴离子杂质的干扰，提高幅度平均约为10％。 (2)当HLB值为15时AKD原粉能得到相对较好的乳化，组成为6-8-9的阴离子复配乳化体系的乳化能力较好，由此而得的乳液具有良好的施胶性能，但是乳液粒径稍大且稳定性方面有所欠缺，作为现场乳化的产品还是可行的。这在以后的研究中还要进一步改进。 (3)自制乳液的施胶度在施胶剂的添加量大于0.15％时比阳离子AKD乳液明显要高；阴离子杂质存在的情况下，自制乳液受干扰的程度比阳离子AKD乳液要小50％；添加填料时，自制乳液的施胶效果好于阳离子AKD乳液，并且添加滑石粉的效果好于GCC；自制乳液对pH的变化适应良好，完全可以满足中性施胶的要求；自制乳液施胶的纸张除抗张强度略差外，其余物理性能均与阳离子AKD乳液进行施胶的纸张差不多，均能满足普通文化用纸的要求。 (4)通过机理研究可知：自制乳液的留着完全依靠PEO助留剂：用于普通文化用纸时AKD-PEO-bemonite的助剂添加顺序较好；硫酸铝的用量越大对施胶度增大越有利，但当用量达到1％后随着硫酸铝用量继续增大，则施胶度又有所下降。 (5)在模拟动态条件下，自制AKD乳液的施胶度要好于阳离子AKD乳液的施胶度，说明自制AKD乳液的动态留着率比阳离子AKD乳液要高。 (6)原浆对AKD粒子的吸附量很小，当加入PEO／膨润土助留体系后吸附量大大增加，再次说明新型AKD粒子的吸附是依靠PEO助留剂的；将浆料筛分开后的吸附实验说明在本研究中这个特定的造纸体系中，长纤维比短纤维对AKD粒子的吸附能力更强。更多还原

【Abstract】 The modern papermaking industry is developing forward to neutral-alkalescence and closed white water system. At the same time, the anionic trash accumulated in circular white water which make the effect of all kinds of wet-end additives (particularly cationic additives) worsen, the wastage and also the cost of papermaking become larger constantly. Now there is a better non-ion retention aid system which composed of poly ethylene oxide (PEO) and bentonite and could resist the interfere of anionic trash preferably. In this paper, the sizing effect of traditional cationic AKD in CPAM/bentonite and PEO/bentonite systems and the sizing effect in condition of the presence of anionic trash were studied. The method of appending some additives to improve the sizing degree was also studied. And the method of changing the component of the emulsifier and ameliorating the technics of emulsification to prepare a new AKD emulsion which can resist the interferer of anionic trash and the applying effect and the retention mechanism of the new AKD emulsion were discussed in this paper. Main results have been obtained as follows:1. The traditional cationic AKD could gain good sizing degree in PEO/bentonite system and CPAM/bentonite system; the sizing degree of cationic AKD emulsion could be strongly interfered by anionic trash in these two retention systems. The average decreasing extent is 30%. The decreasing extent of sizing degree could be advanced by adding water soluble phelonic resin(PFR) to PEO/bentonite system and the increasing extent was about 10%.2. Anionic composite emulsifier composed of 6-8-9, HLB15, dosage20% has a suitable emulsion capacity for AKD, and anionic AKD emulsion made by this way has a good sizing effect. But its stability was not very good and it could be applied as emulsion emulsifing on the spot. This should be improved in the future.3. The sizing degree of new AKD emulsion are higher than that of cationic AKD emulsion when dosage was larger than 0.15% in PEO/bentonite system. The sizing effect of new emulsion is better than cationic emulsion and the decreasing extent interfered by anionic trash is 50% of that of cationic emulsion. When adding fillers to the system, the sizing degree of new emulsion is better than cationic emulsion and the sizing degree of adding talc was higherlhan adding GCC. The new AKD emulsion is adaptive in neutral pH. And the physical properties of paper sized by new emulsion are as well as that of by cationic emulsion except tensile strength which was worse than cationic emulsion. In a word, the physical properties of the paper sized by new AKD emulsion could satisfy the request of fine paper.4. It can be concluded that the retention of new AKD emulsion particles is finished by flocculated with PEO. The best adding orders of additives is AKD-PEO-bentonite when used in fine paper. The sizing degree is increasing with alum. But the sizing degree decreased after the dosage of alum reached to 1%.5. The sizing effect of new AKD emulsion is better than cationic AKD emulsion. It’s show that the dynamic retention ratio of new emulsion is higher than cationic emulsion in PEO/bentonite system.6. The adsorbance of AKD emulsion particles on pulp is very little, while the absorbance become larger after adding PEO/bentonite retention system to it. It also shows that the retention of AKD emulsion particles are performed by PEO. The experiment of absorbance on long fibers and on short fibers shows that the capability of adsorbing AKD particles of long fibers is stronger than short fibers in this specifically papermaking system.更多还原